96-33145. Noise Limitations for Aircraft Operations in the Vicinity of Grand Canyon National Park

[Federal Register Volume 61, Number 252 (Tuesday, December 31, 1996)]
[Proposed Rules]
[Pages 69334-69355]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-33145]



Federal Register / Vol. 61, No. 252 / Tuesday, December 31, 1996 / 
Proposed Rules

[[Page 69334]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 93

[Docket No. 28770; Notice No. 96-15]
RIN 2120-AG34


Noise Limitations for Aircraft Operations in the Vicinity of 
Grand Canyon National Park

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: This notice of proposed rulemaking proposes to establish noise 
limitations for certain aircraft operated in the vicinity of Grand 
Canyon National Park. This notice is one part of an overall strategy to 
reduce further the impact of aircraft noise on the park environment and 
to assist the National Park Service in achieving its statutory mandate 
imposed by Public Law 100-91 to provide for the substantial restoration 
of natural quiet and experience in Grand Canyon National Park. To this 
end, this proposed rule is issued concurrently with a final rule 
affecting the Special Flight Rules in the Vicinity of Grand Canyon 
National Park, a Notice of Availability of Proposed Commercial Air Tour 
Routes for the Grand Canyon National Park and Request for Comments, and 
the Draft Environmental Assessment for this Notice. As mentioned above, 
this NPRM is issued concurrently with a final rule published elsewhere 
in this part of this issue of the Federal Register. Based on Notice No. 
96-11, the final rule adds a new subpart to part 93 to codify and 
revise the provisions of Special Federal Aviation Regulation (SFAR) No. 
50-2, Special Flight Rules in the Vicinity of Grand Canyon National 
Park.

DATES: Comments must be received on or before March 31, 1997.

ADDRESSES: Comments on this NPRM should be mailed, in triplicate to: 
Federal Aviation Administration, Office of the Chief Counsel, 
Attention: Rules Docket (AGC-200), Docket No. 28770, 800 Independence 
Avenue, SW., Washington, DC 20591. Comments may also be sent 
electronically to the Rules Docket by using the following Internet 
address: [e-mail]. Comments must be marked Docket No. 
28770. Comments may be examined in the Rules Docket in Room 915G on 
weekdays between 8:30 a.m. and 5:00 p.m., except on Federal holidays.

FOR FURTHER INFORMATION CONTACT:
Mr. Thomas L. Connor, Mgr, Technology Division, AEE-100, Office of 
Environment and Energy, Federal Aviation Administration, 800 
Independence Avenue, SW., Washington, DC 20591; Telephone: (202) 267-
8933. For the draft Environmental Assessment contact Mr. William J. 
Marx, Division Manager, ATA-300, Federal Aviation Administration, 800 
Independence Avenue, SW., Washington, DC, 20591; Telephone: 202-267-
3075.

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in this proposed 
rulemaking by submitting such written data, views, or arguments as they 
may desire. Comments relating to the environmental, energy, federalism, 
or economic impact that may result from adopting the proposals in this 
notice are also invited. Comments that provide the factual basis 
supporting the views and suggestions presented are particularly helpful 
in developing reasoned regulatory decisions. Communications should 
identify the regulatory docket number and be submitted in triplicate to 
the above specified address. All communications and a report 
summarizing any substantive public contact with FAA personnel on this 
rulemaking will be filed in the docket. The docket is available for 
public inspection both before and after the closing date for receiving 
comments.
    Before taking any final action on this proposal, the Administrator 
will consider all comments made on or before the closing date for 
comments, and the proposal may be changed in light of the comments 
received.
    The FAA will acknowledge receipt of a comment if the commenter 
includes a self-addressed, stamped postcard with the comment. The 
postcard should be marked ``Comments to No. 28770.'' When the comment 
is received by the FAA, the postcard will be dated, time stamped, and 
returned to the commenter.

Availability of the NPRM

    Any person may obtain a copy of this NPRM by submitting a request 
to the Federal Aviation Administration, Office of Rulemaking, 800 
Independence Avenue SW., Washington, DC 20591, or by calling (202) 267-
9677. Communications must identify the notice number of this NPRM. 
Persons interested in being placed on a mailing list for future FAA 
NPRM's should request a copy of Advisory Circular No. 11-2A, Notice of 
Proposed Rulemaking Distribution System, which describes application 
procedures.
    An electronic copy of this document may be downloaded using a modem 
and suitable communications software from the FAA regulations section 
of the Fedworld electronic bulletin board service (telephone: 703-321-
3339) or the Federal Register's electronic bulletin board service 
(telephone: [phone]). Internet users may reach the FAA's webpage 
at http://www.faa.gov or the Federal Register's webpage at http://
www.access.gpo.gov/su__docs for access to recently published rulemaking 
documents.

History

    Beginning in the summer of 1986, the FAA initiated regulatory 
action to address increasing air traffic over Grand Canyon National 
Park (GCNP). On March 26, 1987, the FAA issued Special Federal Aviation 
Regulation (SFAR) No. 50 (subsequently amended on June 15, 1987; 52 FR 
22734) establishing flight regulations in the vicinity of the Grand 
Canyon. The purpose of the SFAR was to reduce the risk of midair 
collision, reduce the risk of terrain contact accidents below the rim 
level, and reduce the impact of aircraft noise on the park environment.
    In 1987, Congress enacted Public Law 100-91, commonly known as the 
National Parks Overflights Act. The Act stated, in part, that noise 
associated with aircraft overflights at GCNP was causing ``a 
significant adverse effect on the natural quiet and experience of the 
park and current aircraft operations at the Grand Canyon National Park 
have raised serious concerns regarding public safety, including 
concerns regarding the safety of park users.''
    Section 3 of Public Law 100-91 required the Department of the 
Interior (DOI) to submit to the FAA recommendations to protect 
resources in the Grand Canyon from adverse impacts associated with 
aircraft overflights. The law mandated that the recommendations: (1) 
Provide for substantial restoration of the natural quiet and experience 
of the park and protection of public health and safety from adverse 
effects associated with aircraft overflight; (2) with limited 
exceptions, prohibit the flight of aircraft below the rim of the 
canyon; and (3) designate flight-free zones except for purposes of 
administration and emergency operations.
    In December 1987, the DOI transmitted its ``Grand Canyon Aircraft 
Management Recommendation'' to the FAA, which included both rulemaking 
and nonrulemaking actions. Public Law 100-91 required the FAA to 
prepare and

[[Page 69335]]

issue a final plan for the management of air traffic above the Grand 
Canyon, implementing the recommendations of the DOI without change 
unless the FAA determined that executing the recommendations would 
adversely affect aviation safety. After the FAA determined that some of 
the DOI recommendations would adversely affect aviation safety, the 
recommendations were modified to resolve those concerns.
    On May 27, 1988, the FAA issued SFAR No. 50-2 revising the 
procedures for operation of aircraft in the airspace above the Grand 
Canyon (53 FR 20264, June 2, 1988) SFAR No. 50-2 established a Special 
Flight Rules Area (SFRA) from the surface to 14,499 feet above mean sea 
level (MSL) in the area of the Grand Canyon. The SFAR prohibited flight 
below a certain altitude in each of five sectors of this area, with 
certain exceptions. The SFAR established four flight-free zones from 
the surface to 14,499 feet MSL above large areas of the park. The SFAR 
provided for special routes for commercial sightseeing operators, which 
are required to conduct operations under part 135, as authorized by 
special operations specifications. Finally, the SFAR contained certain 
terrain avoidance and communications requirements for flights in the 
area.
    A second major provision of section 3 of Public Law 100-91 required 
the DOI to submit a report to Congress ``* * * discussing * * * whether 
[SFAR No. 50-2] has succeeded in substantially restoring the natural 
quiet in the park; and * * * such other matters, including possible 
revisions in the plan, as may be of interest.'' The report was to 
include comments by the FAA ``regarding the effect of the plan's 
implementation on aircraft safety.'' The Act mandated a number of 
studies related to the effect of overflights on parks. The National 
Park Service (NPS) took longer than originally anticipated to complete 
the studies because many of the issues involved are on the cutting edge 
of technical and scientific capability. According to the NPS, measuring 
natural quiet is different from measuring levels of aircraft noise. On 
June 15, 1992, the FAA promulgated a final rule to extend the 
expiration date of SFAR No. 50-2 to June 15, 1995, while the NPS 
studies and analyses were being conducted (57 FR 26764).
    On September 12, 1994, the DOI submitted its final report and 
recommendations to Congress. This report, entitled, ``Report on Effects 
of Aircraft Overflights on the National Park System,'' was published in 
July 1995. The Report recommended numerous revisions to SFAR No. 50-2 
that are described below. The NPS Report was based on more than 20 
separate studies. These studies included acoustical measurements from 
GCNP sites, GCNP visitor surveys, noise dose-visitor response analyses, 
and noise modeling of commercial sightseeing aircraft overflying GCNP 
using FAA survey data.
    The Report concluded that the SFAR had not fully resulted in the 
substantial restoration of natural quiet in the Grand Canyon, despite 
the improvements it brought. Further, as of 1994, only about 34 percent 
of the park could be said to experience a substantial restoration of 
natural quiet, and that this would drop to little more than 10 percent 
by the year 2000 if growth continued at the same level as predicted. 
Only when the NPS made larger flight-free zones and, more importantly, 
substituted quieter aircraft into the scenario modeled for 2010, was 
achievement of a substantial restoration possible. The NPS Report to 
Congress clearly states that reducing noise at the source, as in the 
use of quieter aircraft, is the most important ingredient in achieving 
the substantial restoration of natural quiet in the Grand Canyon.
    On June 15, 1995, the FAA published a final rule that extended the 
provisions of SFAR No. 50-2 to June 15, 1997 (60 FR 31608). This action 
allowed the FAA sufficient time to review the NPS recommendations and 
to initiate and complete any appropriate rulemaking action.
    President Clinton, on April 22, 1996, issued a Memorandum for the 
Heads of Executive Departments and Agencies to address the significant 
impacts on visitor experience in national parks. Specifically, the 
President directed the Secretary of Transportation to issue proposed 
regulations for the Grand Canyon National Park placing appropriate 
limits on sightseeing aircraft to reduce the noise immediately and make 
further substantial progress toward restoration of natural quiet, as 
defined by the Secretary of the Interior, while maintaining aviation 
safety in accordance with Public Law 100-91.
    In response to the President's directive, on July 31, 1996 (61 FR 
40120; Notice No. 96-11), the FAA published an NPRM to reduce the 
impact of aircraft noise on Grand Canyon National Park (GCNP) and to 
assist the NPS in achieving its statutory mandate imposed by Public Law 
100-91 to provide for the substantial restoration of natural quiet and 
experience in GCNP. The NPRM proposed and requested comments on the 
following: (1) Modification of the dimensions of the GCNP SFRA; (2) 
Establishment of new flight-free zones and flight corridors, as well as 
modification of existing flight-free zones and flight corridors; (3) 
Proposed flight-free periods and/or an interim moratorium on additional 
commercial sightseeing air tours and tour operators; and (4) 
Establishment of reporting requirements for commercial sightseeing 
companies operating in the SFRA. In addition to these areas, the FAA 
sought comment on a number of questions and alternatives regarding 
curfews and caps on the number of aircraft and operations, as well as 
on the issue of quiet aircraft technology. The comment period for the 
proposed rule, originally set for 60 days, was subsequently extended 
for another 45 days as directed by the Congress in the Federal Aviation 
Authorization Act of 1996 (61 FR 54716; October 21, 1996). In addition 
several commenters requested additional time to analyze the complex 
components of the proposed rule.
    On September 16-20, 1996, in Scottsdale, AZ, and Law Vegas, NV, the 
FAA held public meetings to obtain additional comment on the NPRM and 
on the draft environmental assessment. Comments and the transcripts of 
these meetings have been placed in the rulemaking docket for Notice No. 
96-11.
    The FAA received approximately 14,000 comments in response to the 
NPRM and the public meetings. The FAA has developed a final rule, based 
on Notice No. 96-11 and on the public comments to the notice, that is 
being issued concurrently with this NPRM published elsewhere in this 
part of this issue of the Federal Register.

Interagency Working Group

    On December 22, 1993, Secretary of Transportation Federico Pena and 
Secretary of the Interior Bruce Babbitt formed an interagency working 
group (IWG) to explore ways to limit or reduce the impacts from 
overflights on national parks, including GCNP. Secretary Babbitt and 
Secretary Pena concur that increased flight operations at GCNP and 
other national parks have significantly diminished the national park 
experience for some park visitors, and that measures can and should be 
taken to preserve a quality park experience for visitors, while 
providing access to the airspace over national parks. The Secretaries 
see the formation of the working group and the mutual commitment to 
addressing the impacts of park overflights as the initial steps in a 
new spirit of cooperation between the two departments to promote an 
effective balance of missions. The FAA has been working closely with 
the NPS to identify and deal with the impacts of

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aviation on parks, and the two agencies will continue to identify and 
pursue the most effective solutions. This close cooperation is 
necessary because the FAA has sole authority for control of the 
nation's airspace to ensure aviation safety and efficiency, while the 
NPS is charged with managing the natural and cultural resources in the 
national park system and providing for public enjoyment of those 
resources in such a manner that they are unimpaired for the enjoyment 
of future generations.
    The FAA's role in the IWG has been to promote, develop, and foster 
aviation safety, and to provide for the safe and efficient use of 
airspace, while recognizing the need to preserve, protect, and enhance 
the environment by minimizing the adverse effects of aviation on the 
environment. The NPS' role in the IWG has been to protect public land 
resources in national parks, preserve environmental values of those 
areas, and provide for public enjoyment of those areas.
    In March 1994, the two agencies jointly issued an advance notice of 
proposed rulemaking (ANPRM) seeking public comment on policy 
recommendations addressing the effects of aircraft overflights on 
national parks, including GCNP (59 FR 12740; March 17, 1994). The 
recommendations presented for comment included voluntary measures, 
altitude restrictions, flight-free periods, flight-free zones, 
allocation of noise equivalencies, and incentives to encourage use of 
quiet aircraft technology. On the issue of possible incentives for 
quiet aircraft technology, the ANPRM stated:

    Air tour operators could be encouraged to use relatively quiet 
aircraft on park overflights. For example, a flight corridor with a 
good scenic view of the canyon could be limited to aircraft meeting 
certain noise emission standards. An air tour operator could find it 
advantageous to convert its entire fleet to such quiet aircraft to 
incorporate that corridor in its tours. While there is no Federal 
requirement for aircraft to be manufactured to produce less noise 
than Stage 3 standards, some aircraft appropriate for air tour 
operations are quieter than Stage 3. Increased use of such aircraft 
in air tours would achieve noise mitigation through reducing noise 
levels on the surface of the park, although this option does not 
address issues other than noise.

    In response to the ANPRM, the FAA received 30,726 comments, 
including duplicate form letters and several petitions with multiple 
signatures; the FAA received 24,510 submissions of one form letter with 
comments addressing the GCNP. Of the total number of comments, 1,975 
were distinct letters. This NPRM will discuss only those comments that 
relate to establishing aircraft noise limitations at GCNP. The 
remainder of the comments relating to the above noted recommendations 
may be addressed in a later rulemaking.
    Of the 644 comments that specifically addressed GCNP, 337 
commenters opposed, while 232 commenters supported, further regulation. 
Commenters included members of State and local governments; 
congresspersons; helicopter operators; Native Americans and other 
individuals; and aviation, environmental, and recreational 
organizations and associations.
    A number of commenters addressed the issue of quiet aircraft 
technology. Commenters opposing additional regulation of aircraft noise 
levels argued that quieter aircraft are expensive and incentives to 
invest in this technology are needed. Alternatively, commenters said 
that noise budgets are too complex and will not work. Commenters 
supporting additional regulation urged that incentives to minimize 
noise per passenger should be established or that an aircraft noise 
budget should be created. Specifically, a few commenters supported the 
unconditional adoption of quiet aircraft technology. One commenter 
suggested dividing aircraft into noise producing classes, with the 
higher noise class airplanes facing greater restrictions. Other 
commenters suggested requiring mufflers for all aircraft. The majority 
of the comments received on this issue, however, raise concerns with 
the adoption of noise-reduction technology. Many commenters stated that 
the cost of quiet plane technology is prohibitive at this time. Some 
commenters suggested adopting noise abatement equipment as it becomes 
affordable. Other commenters suggested using financial incentives--such 
as tax incentives, fee abatements, loan programs, and increased 
allocation on the number of flights allowed--to encourage operators to 
use quiet aircraft. One commenter stated that quiet aircraft technology 
is not an adequate solution for the overflight problem because such 
aircraft retain impacts and risks other than noise. Another commenter 
argued that exploring quiet aircraft technology at this time is not a 
worthwhile endeavor because technology will not be able to address the 
noise problem in the near future. Another commenter stated that, as an 
example for commercial operators, those agencies conducting airflights 
over Noise Sensitive Areas should be required to integrate quieter 
aircraft into their fleets.
    Since the issuance of the joint ANPRM and the formation of the IWG, 
the FAA and NPS have been working closely to identify and deal with the 
impacts of aviation on GCNP, and the two agencies will continue to 
identify and pursue effective solutions. In this spirit of cooperation, 
the agencies plan to take the following nonregulatory and regulatory 
actions to achieve the substantial restoration of natural quiet in 
GCNP.
    In addition to the rulemakings concerning GCNP, the IWG is working 
to develop a nationwide strategy for addressing noise for the national 
park system, and the FAA will be issuing a rule for limiting noise at 
Rocky Mountain National Park.

Public Meetings

    The FAA has held several public meetings in an effort to obtain 
public input for the development of additional actions to reduce the 
impact of aircraft noise on GCNP and assist the NPS in its efforts to 
restore natural quiet and experience in the park.
    On June 28, 1995, the FAA and the NPS jointly published a notice 
announcing a public meeting to provide the interested parties with an 
opportunity to comment on improving SFAR No. 50-2 (60 FR 33452). The 
meeting, held on August 30, 1995, in Flagstaff, AZ, yielded 62 speakers 
representing air tour operators, environmentalists, government, tourist 
boards, corporations, Native American tribes, and other individuals. An 
additional 349 public comments were subsequently received during the 
comment period that ended on September 8, 1995.
    On September 16-20, 1996, in Scottsdale, AZ, and Las Vegas, NV, the 
FAA held public meetings to obtain additional comment on the NPRM and 
on the Draft Environmental Assessment for the final rule that is 
published elsewhere in this issue of the Federal Register. Comments and 
the transcripts of these meetings have been placed in the rulemaking 
docket for that final rule.

Congressional Hearings

    On October 10-11, 1996, Congressional hearings were held by the 
Aviation Subcommittee of the Senate Committee on Commerce, Science, and 
Transportation at Las Vegas, Nevada, and Tempe, Arizona. The hearings 
were held to gather testimony from various entities involved in or 
affected by the FAA's proposed special flight rules over the Grand 
Canyon (Notice No. 96-11). Senator John McCain of Arizona made opening 
statements at both field hearings indicating that they were there

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to examine the impacts of the proposed rules and the Draft 
Environmental Assessment. He hoped the FAA would provide appropriate 
incentives for quiet air technology in the final rule.
    The Nevada Congressional delegation (Senator Bryan and Congressman 
Ensign in person, Senator Reid and Congresswoman Vucanovich by proxy) 
indicated, at the Las Vegas hearing, their opposition to Notice No. 96-
11 as written, noting safety concerns as well as ones related to 
economics, NEPA compliance, and the lack of quite air technology 
incentives.
    The issues raised by Senator McCain and other members of the 
Arizona delegation were also addressed by others testifying at the 
field hearings. There were points (and often counterpoints) raised as 
to the effectiveness of SFAR 50-2 in substantially restoring natural 
quiet in the Grand Canyon, as mandated by Public Law 100-91; the NPS's 
definition of substantial restoration of (50 percent or more of the 
park quiet at least 75 percent of the time); methodology involved in 
measuring and modeling noise impacts; potential impacts of the new rule 
on safety in the SFRA; effects of the new rule on general aviation; 
potential adverse impacts of the rule on the economy of Las Vegas and 
Nevada; the adequacy of the consultation process with Native American 
tribes; and controls on other uses of the park vis-a-vis air tour 
overflights.
    Many of the air tour operators, some of whom had also voiced 
concerns about the safety implications of Notice No. 96-11, predicted 
dire economic consequences for the industry if the NPRM, which included 
possible caps on operations, curfews, and two additional flight-free 
zones, went into effect. In response to the operators' economic 
worries, Senator McCain reminded them that they had unanimously opposed 
his bill, which became Public Law 100-91, in 1987, claiming that it 
would put the entire industry out of business. Instead, he noted, the 
number of air tour overflights of Grand Canyon had increased from 
approximately 40,000 per annum in 1987 to the 95,000 reported by the 
Arizona Republic newspaper for the 12-month period which ended 
September 30, 1996.
    Aside from a commitment to air safety, perhaps the only issue on 
which all of the interests represented at the field hearings appeared 
to agree was the need for quiet air technology incentives for both 
manufacturers and air tour operators. From Senator McCain and members 
of the Nevada Congressional delegation to the Native American tribal 
leaders and from environmental groups to air tour operators and 
aircraft manufacturers, as well as aviation and tourism industry 
representatives, quieter air technology incentives were viewed as 
integral to efforts to substantially restore natural quiet to the Grand 
Canyon while maintaining a viable air tour industry. Among specific 
suggestions made were providing more attractive routes to quieter 
aircraft, setting aside a portion of air tour overflight fees to 
provide loans to air tour operators to invest in further quiet air 
technology, and lowering fees for those operators using quieter 
aircraft.
    The FAA has considered the statements made at the hearings in 
developing this proposed rule.

Consultation With Affected Native American Tribes

    Three Native American reservations border GCNP, and several 
additional tribes have cultural ties to the Grand Canyon. The DOT and 
DOI recognize that before taking any action, they have an obligation to 
consult with these tribes on a government-to-government basis. The 
consultation process, begun with the development of the proposed and 
final rule for the reduction of aircraft noise on GCNP, will continue 
with this process.This will include a continuing dialogue with tribes 
potentially affected by this proposal and will include direct meetings 
as well as written consultation. Initial steps have been taken to 
contact potentially affected tribes of this proposal based on the 
government-to-government relationships.

Relationship to Final Rule Published Concurrently

    As mentioned above, the FAA has developed a final rule, based on 
Notice No. 96-11 and on the public comments to the notice, that is 
being issued concurrently with this NPRM as published elsewhere in this 
part of this issue of the Federal Register.
    Notice No. 96-11 proposed and requested comments on the following: 
(1) Modification of the dimensions of the GCNP Special Flight Rules 
Area (SFRA); (2) Establishment of new flight-free zones and flight 
corridors, as well as modification of existing flight-free zones and 
flight corridors; (3) Proposed flight-free periods and/or an interim 
moratorium on additional commercial sightseeing air tours and tour 
operators; and (4) Establishment of reporting requirements for 
commercial sightseeing companies operating in the SFRA. In addition to 
these areas, the FAA sought comment on a number of questions and 
alternatives regarding curfews and caps, as well as on the issue of 
quiet aircraft technology. The final rule for Notice No. 96-11 
addresses all of these areas except for the issue of quiet aircraft 
technology. The FAA did not include requirements on quiet aircraft 
technology in the final rule, because Notice 96-11 did not propose 
specific measures on that subject; instead the FAA requested comments 
and information that would allow the FAA to develop a specific 
proposal. Based on a review of the comments on quiet technology 
received on Notice No. 96-11, summarized below, the comments received 
at the FAA and Congressional public meetings, the comments received on 
the ANPRM published in 1994, and the NPS Report to Congress, the FAA is 
issuing this NPRM. Comments received to date on quiet technology will 
be considered in conjunction with comments submitted in response to 
this proposed rule.

Comments Concerning Quiet Technology

    One commenter states that the largest operators at the Grand Canyon 
have either converted to quiet technology or are in the process of 
converting.
    Papillon says that quieter aircraft is the solution to the problems 
raised in the NPRM and, in addition to describing the current 
technology available, recommends establishing a time frame for 
transition to quiet technology; establishing guidelines to qualify 
aircraft as quiet; and encouraging and assisting tour operators to 
convert their fleets to quiet technology aircraft.
    Sierra Club-Grand Canyon Chapter says that the goal should be to 
completely phase in quiet technology aircraft over the next 10 to 15 
years, with no increase and even a decrease in the number of flights. 
This commenter says that new aircraft should not be louder than the 
aircraft they replace and that if a noise budget approach is developed, 
there should be a reduction factor.
    The National Parks and Conservation Association (NPCA) asserts the 
necessity of incorporating quiet flight technology into the rule by 
noting that sound can travel 13 to 16 miles laterally from aircraft and 
penetrate deeply into flight-free areas.
    A river tour company notes the use of the Thrush TurboPro for drug 
interdiction. This commenter believes that if the demand were created 
for ``hush kits'' on smaller aircraft via FAA rulemaking, manufacturers 
would develop and produce this type of technology at cheaper prices 
than are currently available.
    Some commenters submitted technical information about quiet

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aircraft that are currently available or being developed. In addition, 
at the Congressional hearing, the National Aeronautics and Space 
Administration (NASA) submitted information on research and development 
efforts (by NASA and the FAA) on quiet aircraft technology for 
propeller-driven airplanes and rotorcraft. The FAA has considered this 
information in developing this proposed rule.
    Some commenters, such as the Grand Canyon Air Tour Association 
(GCATA), Twin Otter, and Grand Canyon Airlines say that the proposed 
rules in Notice No. 96-11 will make it difficult for small operators to 
generate the revenue to invest in quieter aircraft. These commenters 
(some of whom have already employed quieter, more expensive aircraft) 
recommend that incentives such as tax credits, preferred routes and 
altitudes, elimination of overflight fees, and no curfews or caps, be 
made available to tour operators who wish to invest in quieter 
aircraft. Twin Otter and Grand Canyon Airlines add that the use of 
quieter and larger aircraft would be beneficial by reducing the number 
of air tour operations required to carry the same number of passengers, 
which would further reduce noise levels.
    Twin Otter and Grand Canyon Airlines recommend withdrawing the NPRM 
and replacing it with incentives for quiet aircraft technology. Another 
commenter says that the FAA should not take a regulatory approach; 
rather, government should work with private enterprise to develop 
quieter aircraft.
    Some commenters (e.g., Grand Canyon Trust, Wilderness Watch, 
Wilderness Society, Grand Canyon River Guides) state that a stronger 
rule is needed that would provide incentives for conversion of the 
existing tour fleet to the quietest aircraft available. Grand Canyon 
Airlines recommends that interim milestones be set by which existing 
conventional air tour aircraft fleets are converted to quiet aircraft; 
these milestones could be similar in concept to those established in 14 
CFR part 91 for air carrier compliance with 14 CFR part 36 for Stage 3 
certification standards.
    McDonnell Douglas Helicopter Systems (MDHS) supports offering 
economic incentives to encourage air tour operators to operate 
helicopters equipped with quiet technology. Since 1991, MDHS has 
provided many quiet technology ``No Tail Rotor'' (NOTAR) helicopters 
which are operating effectively in noise-sensitive environments. In 
addition to the types of incentives mentioned by other commenters (see 
above), MDHS recommends the use of airspace entry locations based on 
FAA noise certification data for each type of helicopter. MDHS also 
recommends that Federal government agencies operating within the 
national parks should set an example by acquiring and using quiet 
technology aircraft.
    Another commenter suggests allowing those operators who own 
measurably quieter machinery a 5 percent credit on their allotted 
number of flight permits. According to the commenter, operators who 
persist in running noisy aircraft should be subject to penalties 
restricting their permits.
    Another commenter suggests a fee per flight that would encourage 
the use of larger, quieter aircraft by multiplying that fee by the 
sound level. This commenter believes that if this is used in 
conjunction with a limitation on the number of total tour flights 
permitted, operators would be encouraged to use quieter aircraft.
    A BIA representative says that requirements for high-technology 
quiet aircraft should provide a specific exemption to Native American 
tribes for any flights sanctioned by such Native American tribes over 
their own lands.
    The FAA agrees that the use of quieter aircraft will, in the long 
run, provide the most benefit toward restoring natural quiet. As 
discussed later in this preamble, this proposal contains a phase out 
schedule for noisier aircraft, a requirement that newly acquired 
aircraft meet certain acoustic criteria, and an incentive for using 
quieter aircraft by allowing flights though the proposed National 
Canyon route to be conducted with only the aircraft that meet this 
acoustic criteria. The FAA has considered the comments received on 
Notice No. 96-11 in developing the specific proposals described below.
    The FAA and NPS are working together to develop a long-term 
Comprehensive Noise Management Plan that will address the best 
available technology, provision of appropriate incentives for investing 
in quieter aircraft, and appropriate treatment for operators that have 
already made such investments. As discussed below under ``Potential 
Further Action,'' the FAA and NPS solicit comments on the types of 
considerations that should be included in this plan. Both FAA and NPS 
are committed to the development of a noise management plan over the 
next 5 years.

The Proposal

    This proposed rule has several purposes. The first would be to 
provide an incentive for the use of quieter aircraft within GCNP. The 
second would be to establish additional noise limitations to reduce 
further the impact of aircraft noise on the park environment in the 
GCNP. The third would lift for the quietest aircraft the immediate 
temporary cap placed on the number of aircraft permitted to be used for 
commercial sightseeing operations in GCNP.

National Canyon Corridor

    The companion final rule published elsewhere in this part in this 
issue of the Federal Register expands the Toroweap/Shinumo Flight-free 
Zone to prohibit operations in the airspace area that is now used by 
operators for commercial sightseeing operations while flying from Las 
Vegas to Tusayan. This proposal would establish a corridor, referred to 
as the National Canyon Corridor, within the newly expanded Toroweap/
Shinumo Flight-free Zone that would enable operators using GCNP 
Category C aircraft (the quietest category of aircraft, as discussed 
below) to reinitiate commercial sightseeing operations along this route 
from Las Vegas to Tusayan without having to circumnavigate the 
Toroweap/Shinumo Flight-free Zone.

Phase-Out of Noisier Aircraft

    In addition, the purpose of this proposal is to establish 
additional noise limitations to reduce further the impact of aircraft 
noise on the park environment in the Grand Canyon National Park. This 
proposal would accomplish this goal by a combination of requirements 
that would limit future use of noisier aircraft and that would provide 
incentives for the use of quieter aircraft. As discussed below, the 
proposed phase out of the GCNP Category A aircraft would provide a 
major reduction in noise by the end of the year 2000 and make a major 
contribution toward achieving the Congressional mandate of substantial 
restoration of natural quiet. Modeling shows that, if the phase out is 
adopted as proposed, the substantial restoration objective would be 
exceeded by 2008. The subsequent phase out of GCNP Category B aircraft 
would ensure continued restoration of natural quiet, as required by the 
NPS, even when projected numbers of additional GCNP Category C aircraft 
are added to the commercial sightseeing fleet.
    The FAA has evaluated the noise exposure of existing aircraft used 
in the GCNP and has divided those aircraft into three categories based 
on noise per passenger or ``noise efficiency'': GCNP Category A 
aircraft includes the least noise efficient aircraft currently in use 
for sightseeing operations in the vicinity

[[Page 69339]]

of the Grand Canyon National Park; GCNP Category B aircraft includes 
aircraft more noise efficient than Category A aircraft but less noise 
efficient than the quietest aircraft now available; and GCNP Category C 
aircraft includes affected aircraft which are the quietest currently 
available. A detailed discussion of the technological basis for these 
categorizations is in the following section of this preamble, entitled 
``Quiet Technology for GCNP.''
    This proposal would in effect prohibit any further acquisition of 
GCNP Category A aircraft for use in the SFRA by persons conducting 
sightseeing operations. Current operators with Category A aircraft 
could continue to use that number of GCNP Category A aircraft listed on 
the operator's operations specifications on December 31, 1996, but that 
use of GCNP Category A aircraft would have to end on or before December 
31, 2000.
    Current operators of GCNP Category B aircraft would be allowed to 
continue to use that number of aircraft listed on the operating 
specifications as of December 31, 1996, and on or before December 31, 
2000, as a replacement for GCNP Category A aircraft, but would be 
required to phase out all of those aircraft on or before December 31, 
2008. The proposed phase out schedule would require that on or before 
December 31, 2002, at least one-quarter of the number of Category B 
aircraft listed on the operator's operations specifications on December 
31, 2000, (the base level) would have to be phased out. The remaining 
Category B aircraft would have to be phased out in 25 percent 
increments so that no more than 50 percent of the base level aircraft 
would be in use after December 31, 2004, 25 percent after December 31, 
2006, and all Category B aircraft would have to be phased out on or 
before December 31, 2008. During the period of time after the effective 
date of a final rule and on or before December 31, 2000, an operator 
could replace Category A aircraft with Category B or C aircraft but 
only on a one-for-one basis.
    While the proposed rule would allow the continued use of Categories 
A and B aircraft by current certificate holders as described above, all 
aircraft used by new entrants to the affected sightseeing area would 
have to meet Category C requirements. This means that any person who 
wants to establish an aircraft sightseeing operation in the affected 
area after the effective date of a final rule would have to use only 
Category C aircraft. Also, all new aircraft acquired by present 
operators above the total number of Category A and B aircraft listed on 
the operations specifications of each operator on December 31, 1996, 
would have to be Category C aircraft.
    The FAA is soliciting comments on all aspects of the proposed 
phase-out plan, including the affected aircraft, the schedule and 
percentage of aircraft that would be affected by any such plan. 
Comments focusing on the economic and environmental impact of the 
proposed phase-out would be beneficial.

Comments on Alternative Proposal

    Comments are particularly requested on a potential alternative to 
the proposal to allow an operator to replace Category A aircraft with 
either Category B or Category C aircraft. Under the alternative, 
Category A aircraft could only be replaced by Category C aircraft. No 
interim replacement by Category B would be permitted. Because this 
would hasten the elimination from the GCNP of all aircraft other than 
Category C, it is likely to achieve the goal of attaining natural quiet 
more rapidly than the primary proposal set forth in this notice. This 
alternative was not incorporated into the current proposal, however, 
because the FAA's preliminary analysis suggests that it could be 
significantly more costly to operators. (See the Appendix to the 
Regulatory Evaluation contained in the docket.) These costs could be 
particularly burdensome to small entities.
    However, if the additional costs of a direct transition from 
Category A to Category C are lower than they currently appear, and 
substantial additional environmental benefits may be obtained at 
reasonable cost, the final rule adopted in this proceeding could 
incorporate the alternative approach. Before taking final action, 
therefore, the FAA intends to further refine its cost estimates and the 
likely burden on small operators. Toward that end, it would be 
especially helpful if commenters provide specific cost and 
environmental projections that compare the impact of the primary 
proposal with the alternative. The FAA requests answers to the 
following questions, along with any other relevant information 
commenters wish to provide. Please note that comments accompanied by 
specific data about costs and/or environmental effects will be more 
useful than arguments of a general nature.
     From a business economic standpoint, would allowing the 
interim conversion of Category A aircraft to Category B be less 
burdensome than direct conversion to Category C?
     Does the cost of Category C aircraft exceed the cost of 
Category B aircraft? If so, by how much? What options other than direct 
purchase of Category C aircraft would be available that may have an 
effect on the economics of conversion?
     What is the availability of used Category C aircraft, and 
how could the acquisition of used aircraft mitigate the cost of the 
alternative?
     Are there business reasons that would cause operators to 
choose to replace Category A aircraft with Category C, even if Category 
C aircraft are more expensive than Category B aircraft? For example, 
would the subsequent need to phase out Category B make the option of an 
interim step undesirable in any event? Similarly, do Category C 
aircraft offer advantages in operating efficiency, marketability of air 
tours, repair costs, or other factors that would reduce the overall 
cost differences between acquiring Category B and Category C aircraft?
     Would other methods of analysis that include such factors 
as the cost of capital, long-term tax consequences, and other factors 
be more useful in determining the economic impacts of the conversion? 
If so, how should those factors be taken into account?
     What would be the noise-reduction consequences of 
requiring a direct transition from Category A to Category C? The 
replacement of Category A aircraft (by either Category B or Category C) 
is likely to make the greatest contribution toward the restoration of 
natural quiet. Insofar as quantification is possible, it would be 
useful to understand how much additional benefit could be obtained by 
going directly to Category C.

Removal of Temporary Cap

    Under the companion final rule published today, an immediate 
temporary cap is placed on the number of aircraft permitted to be used 
by each operator for commercial sightseeing operations in the Grand 
Canyon SFRA. If this notice is adopted as proposed, a cap on the total 
number of Category A and Category B aircraft permitted to operate in 
GCNP would remain in effect. However, the cap on Category C aircraft 
would be lifted. As a result, the fleet size of Category C aircraft 
could grow, subject to safety considerations, market-based 
considerations, or recommendations from the Comprehensive Noise 
Management Plan. For a more detailed discussion of this issue, see 
``Potential Further Action'' below.

Quiet Technology for GCNP

    This section of the preamble is a summary of a technical paper 
describing the methodology for classifying noise characteristics for 
aircraft operating in

[[Page 69340]]

GCNP. The full document has been placed in the docket for this 
rulemaking and is available for viewing and comment as described above 
under ADDRESSES. To obtain a copy of this document, contact the person 
listed under FOR FURTHER INFORMATION CONTACT.

Introduction

    In response to comments in the docket for Notice No. 96-11 and 
those made at public hearings, FAA redoubled its efforts to develop 
concepts which would provide incentives for tour operators to invest in 
the best available noise abatement technology. Traditionally, the FAA 
uses its regulatory authority to impose more stringent national noise 
standards when it has been determined to be appropriate. By law when 
deciding on further noise stringency, FAA must ascertain whether the 
proposal is technologically feasible, economically reasonable, and 
appropriate to aircraft type. Based upon a joint FAA/NASA research 
report to Congress on quiet technology \1\ and earlier work prepared 
for the third meeting of the Committee on Aviation Environmental 
Protection (CAEP) under the International Civil Aviation Organization 
(ICAO), the FAA determined that the imposition of new national and 
international noise standards for propeller-driven small airplanes and 
helicopters is not appropriate at this time. While there is ongoing 
research by the Federal government to identify future noise abatement 
technology, current aircraft designs already incorporate most of the 
available technology within economic reasonableness. At GCNP, there are 
substantive differences in the noise characteristics of the air tour 
aircraft in use. Therefore, FAA looked to non-traditional concepts 
which could offer some incentive for tour operators to improve the GCNP 
situation.
---------------------------------------------------------------------------

    \1\ Report of the FAA and NASA to the U.S. Congress Pursuant to 
Section 308 of the FAA Authorization Act of 1994, ``Quiet Aircraft 
Technology for Propeller-driven Airplanes and Rotorcraft,'' June 
1996.
---------------------------------------------------------------------------

Noise Efficiency Concept

    One theme expressed by some commenters was that the use of quieter, 
larger aircraft would provide two-fold benefits in reducing noise of 
each operation and reducing the number of operations to carry the same 
number of passengers. This theme fits in nicely with the FAA's general 
policy of using cumulative aircraft noise as an appropriate measure of 
the potential impact as it accounts for both the number of flights and 
intensity of their noise. The FAA began to explore noise efficiency 
concepts as an incentive for operators to utilize aircraft equipped 
with the best available noise abatement technology in the park. The 
following attributes were used in judging potential concepts:
     Is based on aircraft noise certification (14 CFR part 36).
     Judges fixed- and rotary-wing aircraft on a common basis.
     Correlates with aircraft performance and operation at 
GCNP.
     Offers basis for incentives.
     Is manageable.
    In addition to these attributes, the concept must be shown to be 
economically reasonable.

Links to Aircraft Noise Certification

    Levels obtained from aircraft noise certification represent the 
highest quality of data available. The flight tests are conducted under 
controlled conditions with an FAA representative or designee in 
attendance to witness the test setup and test activities. Data obtained 
during these tests are corrected to standard reference conditions as 
prescribed in 14 CFR part 36. FAA publishes these levels in Advisory 
Circular 36-1, ``Noise Levels for U.S. Certificated and Foreign 
Aircraft.'' The current version of this AC is 36-1F dated 6/5/92. 
Unfortunately there is no single method applicable to all aircraft for 
determining the certificated noise level. Depending on date of 
application for type certificate and whether the aircraft is a 
helicopter or airplane, the noise level could have been obtained from 
one of 4 different tests, Appendices F, G, H, and J of 14 CFR part 36.
    Because these noise certification procedures contain differences in 
aircraft operation, measurement altitudes, and units of noise, it is 
not possible to directly compare Appendix F, G, H, and J noise levels. 
However, FAA has developed a procedure for: (1) Extrapolating from the 
controlled conditions of a certification test to the operating 
conditions at GCNP and (2) converting levels to a common noise unit, 
thus making it possible to judge fixed- and rotary-wing aircraft on a 
common basis under conditions that pertain to air tour operations over 
GCNP. Sound Exposure Level (SEL) was selected as the common noise unit. 
SEL is a basic building block in calculating Equivalent Sound Level 
(Leq) which is the measure of cumulative noise exposure that FAA 
is using to assess noise impacts in GCNP. (Leq) is the most common 
method used to quantify time-varying noises. The Federal government 
uses a form of equivalent sound level, Day Night Sound Level (DNL), to 
quantify aircraft noise exposure in the vicinity of airports.

Noise Efficiency Measure

    These extrapolation procedures for predicting noise levels 
applicable to Appendices F, H, and J of 14 CFR part 36 enable one to 
directly compare propeller-driven small airplanes and helicopters. 
There is no extrapolation procedure for Appendix G. The noise 
efficiency criterion for Appendix G noise levels was derived by a 
method that is explained later. In keeping with the theme of developing 
a noise efficiency concept, the extrapolated noise levels were examined 
as a function of the number of seats of the aircraft in the fleet of 
air tour aircraft operating at GCNP. Since the principal business of 
these aircraft is to carry sightseers over the park, the number of 
passenger seats is a logical production (or efficiency) factor.
    When the aircraft noise levels are plotted against the number of 
passengers, there appears to be a break or gap between groups of 
aircraft that support some NPS findings on ``quiet aircraft.'' The NPS 
report to Congress identifies the DHC-6-300 Twin Otter (``Vistaliner'' 
version), the Cessna Caravan I, and the McDonnell Douglas ``No Tail 
Rotor'' (NOTAR) helicopters as the quietest aircraft currently 
operating at GCNP. The report further states that NPS expects that 
these aircraft would qualify under a ``quiet aircraft'' category.
    A line of a demarcation can be drawn between the quietest aircraft 
and the rest of the air tour fleet. The two components of the line are: 
(1) Horizontal until greater than 2 passenger seats, and (2) increasing 
slope at 3 dB per doubling of number of seats. The line is horizontal 
until the number of seats is greater than 2 because a review of 
aircraft specification data found that two is the least number of 
passenger seats found on an aircraft that had been operated as an air 
tour aircraft in GCNP. Specifying a limit that increases with the 
number of seats is consistent with FAA's philosophy of rewarding 
efficiency by allowing aircraft which carry more passengers to emit 
more noise, thus creating less noise per passenger. For example, the 
slope of Appendix H noise limit increases at the rate of 3 decibels per 
doubling of weight. For aircraft in these weight ranges, 3 dB per 
doubling of number of seats is a comparable growth rate to 3 dB per 
doubling of weight. Figure 1 shows noise levels of many of the air tour 
aircraft against the number of passenger seats in the aircraft.

[[Page 69341]]

    The area below the solid line in Figure 1 is proposed as the 
potential objective in the encouragement of compatible noise abatement 
technology for air tour operations in GCNP. This area is labeled ``C'' 
and the aircraft whose SELs fall within this region are ``GCNP Category 
C aircraft.'' Another dotted line is plotted at 4 decibels above the 
solid line in Figure 1 which creates two new areas each covering 4 
decibels and evenly splits the number of air tour aircraft into these 
two zones. The two new areas are labeled ``A'' and ``B.'' Aircraft 
whose noise levels fall within these new zones are identified as GCNP 
Category A and GCNP Category B aircraft, respectively. An examination 
of a recent count of air tour aircraft finds that there are 57 GCNP 
Category A aircraft, 56 GCNP Category B, and 23 GCNP Category C 
aircraft operating at GCNP.

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Noise Efficiency Criteria

    The curves in Figure 1 demonstrate the general concept and are the 
bases for the noise efficiency criteria. A workable criterion should be 
easy to apply and manage in the field and should be understandable to 
the operators and general public. The airport community has many years 
of experience using the certificated noise levels published in FAA's AC 
36-1F. These data have been used to establish use restrictions, 
curfews, and noise budgets at some airports in the country. The 
certificated noise levels are not only available in advisory circulars 
which are updated and published periodically but the levels are readily 
available to the aircraft owners from the aircraft flight manuals 
(AFM). Thus the development of noise efficiency criteria based on 
certificated noise levels is proposed not only because of the 
precedent, but it also eliminates the need for someone in the field to 
perform the mathematical extrapolation from certification to GCNP 
conditions by the method that was outlined in the section ``Links to 
Aircraft Noise Certification.''
    By reversing the process that determined the noise levels in Figure 
1, the two lines in Figure 1 are translated into three GCNP noise 
efficiency criteria for Appendices F, H, and J. These are shown in 
Figures 2a, 2b, and 2c, respectively. The figures also contain the 
equations for the GCNP Categories B and C noise efficiency criteria or 
noise limits. These are the criteria for compliance with the proposed 
regulation.
    As stated earlier, this study did not discover a method to 
successfully extrapolate Appendix G noise levels to GCNP conditions. 
When FAA promulgated Appendix G to supersede Appendix F, the change was 
to replace the level flyover test with a takeoff test. The Appendix G 
noise limit is 5 decibels higher than the Appendix F noise limit to 
account for difference in measured noise levels obtained under the 
different test conditions. Applying that philosophy to this situation, 
a noise efficiency criterion for Appendix G noise levels can be derived 
by adding 5 decibels to the criteria for Appendix F. There is no figure 
in this paper, similar to Figures 2a-c, showing the Appendix G noise 
efficiency criteria because all of the propeller-driven airplanes 
currently operating at GCNP predate the promulgation of Appendix G of 
14 CFR part 36. The equations of the noise efficiency criteria for 
Appendix G are found in Appendix B of the proposed rule.

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[[Page 69345]]

Implementation

    The proposed GCNP aircraft noise incentive concept links to the 
aircraft noise certification provisions prescribed in 14 CFR part 36. 
The incentive criteria will be based upon the noise levels obtained 
under noise certification conditions. The use of noise certification 
levels will provide an ability to judge fixed- and rotary-wing aircraft 
on a common basis.
    New aircraft are subject to the provisions of 14 CFR part 36 
including the requirement to conduct a noise certification test under 
controlled conditions. This test is conducted in accordance with an FAA 
approved test plan and is typically witnessed by FAA personnel unless 
delegated to an FAA designee. Some aircraft, depending on the date of 
type certification, were not subject to the noise certification 
provisions of 14 CFR part 36. Thus noise certification levels are 
unknown. In the strict sense certification noise tests should be 
required to establish noise levels for comparative purposes against the 
GCNP aircraft noise efficiency criteria.
    The FAA does not have the authority to mandate that those older 
aircraft conduct such tests for compliance with the provisions of 14 
CFR part 36. However, in order to fully implement the GCNP aircraft 
noise incentive concept, noise certification levels or estimates of 
those levels under certification conditions will be required.
    Considering the overall cost associated with conducting noise 
certification tests and establishing noise certification levels it is 
proposed to offer a hierarchy of noise level data source options for 
establishing noise levels to fully implement the GCNP aircraft noise 
incentive concept. FAA plans to publish an Advisory Circular (AC 36-XX) 
that will facilitate the determination of the noise levels for the GCNP 
noise efficiency criteria. This AC would list all aircraft operating at 
Grand Canyon National Park as determined from operations 
specifications. Noise levels would be specified for each aircraft 
listed in the AC.
    In some cases the noise levels listed in this proposed AC would be 
the actual FAA approved noise certification levels documented in the 
FAA approved airplane or rotorcraft flight manuals. These level are 
typically provided in FAA AC 36-1 and would simply be referenced in the 
proposed GCNP AC. In other cases where noise certification under 14 CFR 
part 36 was not required, the noise level could be provided to the FAA 
by the operator or owner following the hierarchy described below. The 
owner or operator would have to substantiate to the FAA that the 
estimated noise level is representative for the subject aircraft.
    The following hierarchy of noise level data sources would be 
documented in the proposed AC and used for all aircraft in determining 
the noise level for the GCNP aircraft noise incentive concept:
    1. US certifications under 14 CFR part 36 with noise certification 
levels obtained from the FAA approved flight manuals or FAA AC 36-1.
    (a) For propeller driven small airplanes the applicable hierarchy 
of regulations are:
    (1) 14 CFR part 36 Appendix F.
    (2) 14 CFR part 36 Appendix G.
    (b) For helicopters the applicable hierarchy of regulations are:
    (1) 14 CFR part 36 Appendix J.
    (2) 14 CFR part 36 Appendix H.
    2. Foreign certifications under ICAO Annex 16, Volume I with noise 
certification levels obtained from the approved flight manuals or data 
approved by the foreign civil aviation authorities, or FAA AC 36-1.
    (a) For propeller driven small airplanes the applicable hierarchy 
of regulations are:
    (1) ICAO Annex 16, Volume I Chapter 6.
    (2) ICAO Annex 16, Volume I Chapter 10.
    (b) For helicopters the applicable hierarchy of regulations are:
    (1) ICAO Annex 16, Volume I Chapter 11.
    (2) ICAO Annex 16, Volume I Chapter 8.
    3. Research or other measurement test data obtained under 
controlled conditions, documented and corrected to the certification 
conditions of Appendix F for small propeller driven airplanes and 
Appendix J for helicopters. Preference would be placed on those data 
obtained under certification-like conditions and/or those data 
collected under an FAA sponsored noise research test.
    4. FAA approved noise estimation methods that can estimate Appendix 
F noise levels for small propeller driven airplanes and Appendix J 
noise levels for helicopters. Currently the following methods may be 
suitable for use pending FAA approval on a case by case basis.
    (a) For propeller driven small airplanes: Method in Section 2.2 of 
DOT/FAA/AEE-82-1.
    (b) For helicopters: SAE/AIR 1989.
    As one moves down on the hierarchy the expected level of 
substantiation (as the representative noise certification level-
estimated) by the operator or owner would increase, and the level of 
FAA scrutiny should be expected to increase.
    The resulting noise levels will vary depending upon an operator's 
or owner's situation related to the above hierarchy. In the case of 
helicopters the noise levels will be the flyover noise certification 
level in the noise metric of Effective Perceived Noise Level (EPNL) (14 
CFR part 36, Appendix H) or Sound Exposure Level (SEL) (14 CFR part 36, 
Appendix J). In the case of small propeller-driven airplanes the noise 
levels will be the flyover (14 CFR part 36, Appendix F) or takeoff (14 
CFR part 36, Appendix G) noise certification level in the noise metric 
of maximum A-weighted sound level. It is estimated that noise levels 
for virtually all aircraft currently operating in GCNP could be 
achieved without the need for a complete noise certification test.
    All estimated noise certification levels provided in the proposed 
FAA AC 36-XX would be for the sole and specific purpose of determining 
compliance with Grand Canyon noise efficiency criteria.

NPS Air Operations

    GCNP has one of the most strictly regulated aviation programs 
within the NPS and the DOI. The park limits use of its contracted 
aircraft to activities involving life or health-threatening 
emergencies, administration and/or protection of resources, and for 
individually approved special purpose missions. Each flight request is 
reviewed to ensure that it is the most efficient, economical, and 
effective method of performing the required task consistent with NPS 
and GCNP goals. These goals include the protection of natural quiet and 
experience, as reinforced by the park's recently approved General 
Management Plan. The NPS is revising its contract requirements so that 
it can contract for quieter aircraft that meet mission requirements, 
and it is addressing this in budget formulation as a high priority 
need. The NPS will, to the maximum extent possible, meet or exceed 
phase-out schedules for the air tour industry at large and will to the 
maximum extent feasible honor flight-free zones established for the 
Park. GCNP seeks to make this conversion in advance of the requirements 
of this rule.

Development of a Comprehensive Noise Management Plan

    This proposed rule reflects the understanding of the FAA and NPS 
that the conversion of the commercial sightseeing aircraft fleet 
operating in the SFRA to a more noise efficient fleet is

[[Page 69346]]

the most promising approach to providing for the substantial 
restoration of natural quiet mandated by Public Law 100-91 and allowing 
for some measure of growth in the commercial sightseeing industry. To 
ensure that the proposed rule provides the fairest solution for all 
parties involved, the FAA and NPS are committed to the joint 
development of a noise management plan no later than 5 years from May 
1, 1997. It will provide for a more adaptive management system, full 
resolution of all monitoring and modeling issues, improved public 
input, and the provision of improved incentives to invest in noise 
efficient aircraft. The purpose is to further refine the final rule 
published concurrently with this proposed rule, whose intent is to 
provide for the substantial restoration of natural quiet mandated by 
the Overflights Act. To ensure development of a flexible and adaptive 
approach to noise mitigation and management, this plan will, at a 
minimum, (1) address development of a reliable aircraft operations and 
noise database, (2) validate and document the most effective uses for 
FAA and NPS noise models in GCNP, (3) explore how the conversion to a 
noise efficient fleet can most effectively contribute to the 
substantial restoration of natural quiet while allowing for growth in 
the industry, and how, in this context, incentives can best be provided 
to promote this conversion. The FAA and the NPS are committed to an 
open process that will provide for full public involvement.
    In the development of the Comprehensive Noise Management Plan, 
consideration will be given to the inclusion of additional reporting 
requirements. The final rule published elsewhere in this part of this 
issue of the Federal Register does not require that operators report on 
their commercial sightseeing operations and aircraft used with the SFRA 
beyond the year 2002. Some type of additional information after that 
time will be required. The FAA is requesting comments on the type of 
information and the method of collecting that information that would be 
most consistent with this plan. Comments will be considered during the 
development of the Comprehensive Noise Management Plan.

Potential Further Action

    As proposed, the FAA would remove the temporary cap placed on 
certain aircraft permitted to be used for commercial sightseeing 
operations in GCNP. This is in response to the cap established by the 
companion final rule published elsewhere in this part in this issue of 
the Federal Register.
    The proposed rule would permit operators conducting commercial 
sightseeing operations within the SFRA to replace GCNP Category A 
aircraft with GCNP Category B aircraft until December 31, 2000. 
According to the proposed requirements of the phase-out, the GCNP 
Category B aircraft could be used until December 31, 2008. Furthermore, 
the proposed rule allows the substitution of GCNP Category B aircraft 
with other GCNP Category B aircraft until December 31, 2008. In this 
context, should operators be restricted to replacing either GCNP 
Category A and B aircraft only with GCNP Category C aircraft?
    As proposed in this notice, the removal of the cap would enable the 
fleet size to grow. Fleet conversion to larger and quieter aircraft 
provides for industry growth and noise reduction. But since there is 
ultimately some capacity level that is consistent with the substantial 
restoration of natural quiet, which the FAA and NPS will address in the 
development of a Comprehensive Noise Management Plan, the FAA is 
requesting specific comment on how to address this ``capacity'' issue:

--Should an overall cap on the fleet size be maintained until the 
Comprehensive Noise Management Plan is completed? Or should the number 
of Category C aircraft in the fleet be allowed to grow through random 
addition until it reaches the size recommended in the Comprehensive 
Noise Management Plan to be in concert with one that will maintain the 
substantial restoration of natural quiet in GCNP?
--At what size should the fleet be capped? What is the appropriate 
baseline to establish for imposition of a fleet cap? And if imposed, 
what would the effect be on transitioning to noise efficient aircraft? 
What provisions should be made for changes in technology that result in 
increased aircraft efficiency and sound reduction?
--Should incentives be included in a ``flexible'' cap that would permit 
increasing numbers of aircraft based on acquisition of leading edge 
noise efficient technology by operators? Should growth be tied to an 
incentive system for existing operators to convert their fleet to more 
noise efficient aircraft? For example, an operator converting two GCNP 
Category A aircraft to GCNP Category C aircraft could add an additional 
GCNP Category C aircraft, for a total of three GCNP Category C 
aircraft. And an operator converting three GCNP Category B aircraft 
would be permitted to add one additional GCNP Category C aircraft, for 
a total of four GCNP Category C aircraft.
--Should caps be applied more selectively to specific routes or 
corridors that are more noise-sensitive, such as the Dragon Corridor?

    The FAA is specifically requesting comments on how to better 
protect areas adjacent to the Dragon Corridor, identified by the NPS as 
among the most noise-sensitive areas in the GCNP. To minimize the 
amount of noise from commercial sightseeing aircraft in the Dragon 
Corridor, the FAA solicits comments on the following alternatives:
     Removing the two-way loop permitted for helicopters in the 
Dragon Corridor and reinstating the two-way loop in the Zuni Corridor.
     Accelerating the proposed phase-out schedule for aircraft 
operating in the Dragon Corridor.
     Permitting only GCNP Category C aircraft to operate in two 
directions within the Dragon Corridor.

Environmental Review

    The FAA has prepared a draft environmental assessment (EA) for this 
proposed action to assure conformance with the National Environmental 
Policy Act of 1969. A copy of this draft EA will be circulated to 
interested parties and placed in the docket, where it will be available 
for review. For those unable to view the document in the docket, the 
Draft EA can be obtained from the person listed in the FOR FURTHER 
INFORMATION CONTACT section listed previously. The comment period on 
the Draft EA will remain open for 90 days from the date of the 
publication of this Notice. Before the final rule is issued, the FAA 
will prepare a Final EA and determine whether a Finding of No 
Significant Impact may be issued or an environmental impact statement 
is required.

Regulatory Evaluation Summary

    Changes to federal regulations must undergo several economic 
analyses. First, Executive Order 12866 directs Federal agencies to 
promulgate new regulations or modify existing regulations only if the 
potential benefits to society justify the costs. Based on the criteria 
outlined in E.O. 12866, the Department of Transportation has concluded 
that this rulemaking would constitute a ``significant regulatory 
action'' and, as such, must include an analysis of alternative actions. 
Second, the Regulatory Flexibility Act of 1980 requires agencies to 
analyze the

[[Page 69347]]

economic impact of regulatory changes on small entities. Finally, the 
Office of Management and Budget directs agencies to assess the effects 
of regulatory changes on international trade.
    In conducting these assessments, the FAA has determined that the 
combined quantifiable and non-quantifiable benefits of the proposed 
rule would exceed costs. The FAA has also determined that the rule 
would not have any significant impact on international trade. In 
addition, the FAA has estimated that the rule would have a significant 
economic impact on a substantial number of small air tour operators. 
Therefore, a regulatory impact analysis is included as required by law. 
These analyses, available in the docket, are summarized below.

Introduction

    This regulatory evaluation analyzes the costs and benefits of the 
proposed rulemaking to establish noise limitations for certain aircraft 
operations over the Grand Canyon National Park (GCNP). The FAA is 
proposing these limitations to reduce the impact of aircraft noise on 
the park environment and to assist the National Park Service in 
achieving its statutory mandate imposed by Public Law 100-91. Public 
Law 100-91 mandates for the substantial restoration of natural quiet 
and experience in GCNP. Responding to the law, this proposal would 
assure the achievement of that mandate through a combination of 
requirements that would limit the future use of noisier aircraft and 
provide incentives for the use of quieter aircraft. This NPRM is issued 
concurrently with a final rule which codifies and revises the 
provisions of Special Federal Aviation Regulation (SFAR) No. 50-2, 
Special Flight Rules in the Vicinity of Grand Canyon National Park.

Costs

    The FAA estimates that the undiscounted cost of the proposed rule 
to be $172.6 million, with a present value of $96.7 million. This cost 
estimate was calculated for the 12-year period, 1997 to 2008, and would 
be incurred by operators conducting airtour operations at the GCNP. 
Most of this cost would result from operators having to ultimately 
replace their Category A and B aircraft with Category C aircraft. Each 
of the cost categories are described below. The assumptions used to 
calculate the costs are explained in detail in the full regulatory 
evaluation.\2\
---------------------------------------------------------------------------

    \2\ As required by the Office of Management and Budget (OMB), 
the present value of this stream was calculated using a discount 
factor of 7 percent. All dollar values are expressed in 1995 
dollars.
---------------------------------------------------------------------------

    The FAA has identified five cost components in the NRPM. These 
components and their respective costs are explained below.

Cost of Certifying Noise Efficiency

    Four aircraft--CE-180, CE-206, PA-28-180, and BHT-206-B--predate 
the noise standard and, therefore, do not have certificated noise 
levels. To obtain a noise level to use to compare with the GCNP noise 
efficiency limit, either a computational analysis or a measurement test 
is required. The estimated costs for this are $18,750 for each aircraft 
type, and would occur in 1997, so the total cost would be $75,000 (net 
present value, $70,000).\3\
---------------------------------------------------------------------------

    \3\ While it is possible in the future that another aircraft 
would be introduced into the GCNP that does not have a certified 
noise level, such a situation is impossible to predict. All Category 
B and C aircraft that this analysis assumes airtour operators would 
convert to have certified noise levels, so no additional costs are 
anticipated in the future for this cost component.
---------------------------------------------------------------------------

Cost of Phase-Out

    Another cost of the NPRM is the eventual phase-out of Category A 
and Category B aircraft and replacement with Category C aircraft. 
Specifically, the cost represents the difference in value of existing 
aircraft and their replacements and the additional or differential 
expenses associated with operating the quieter aircraft.
    Phase-Out of Category A for Category B Aircraft: The aircraft value 
differential was calculated by subtracting the value of Category A 
aircraft from the value of Category B aircraft. The operating cost 
differentials were similarly calculated and added over the period 1997 
to 2000. These aircraft would subsequently need to be replaced by 
Category C aircraft between 2001 and 2008. The analysis assumes that 
each existing Category A aircraft would be replaced by a PA-31-350 by 
2000, which would then be replaced by a Caravan by 2008. The cost of 
phasing out Category A for Category B aircraft (and subsequently for 
Category C aircraft) is $74 million, with a present value of $42 
million.
    The FAA considered the option of requiring phased-out Category A 
aircraft to be replaced directly with Category C aircraft instead of 
allowing operators to temporarily replace Category A aircraft with 
Category B aircraft. This option was rejected because requiring direct 
conversion to more expensive Category C aircraft would place a major 
economic burden on many small business operators during the first four 
years of the phase-out (1997-2000). The FAA estimates that $72 million 
more in costs would occur in this period as a result of this option 
than if transition to Category B was allowed. Some operators may choose 
to convert directly from Category A to Category C aircraft since it 
must be done by 2008 anyway, but allowing the flexibility to convert 
from A to B to Category C provides economic relief to those operators 
who need it most by allowing them to spread costs over a much longer 
period and generate additional revenues to offset these costs. Direct 
conversion from Category A to Category C results in some small earlier 
noise reductions in the Park, but both approaches lead to the same 
benefits by the year 2008.
    Phase-Out of Category B for Category C Aircraft: The aircraft value 
differential was calculated by subtracting the value of Category B 
aircraft from the value of Category C aircraft. (See full regulatory 
evaluation for list of aircraft.) The operating cost differentials were 
similarly calculated and added over the period 2001 to 2008. The cost 
of phasing out Category B for Category C aircraft by 2008 is $62 
million, with a present value of $34 million.

Cost of Non-Addition for Category A Aircraft

    This non-addition cost is the cost associated with prohibiting 
additions of Category A aircraft that would otherwise occur in the 
absence of the proposed rule. It is the cost differential between the 
price of Category B or C aircraft and Category A aircraft. From 1997 to 
2000, all Category A aircraft would need to be converted to Category B 
aircraft. Thereafter, all Category A aircraft would have to become 
Category C aircraft. Twelve-year costs sum to $22 million with a 
present value of $12 million.

Cost of Non-Addition for Category B Aircraft

    Similarly, non-addition cost for Category B aircraft is the cost 
associated with prohibiting Category B additions except for replacement 
of Category A aircraft. It is the cost differential between the price 
of Category B aircraft and a Category C aircraft had this proposed rule 
not been in place. This analysis makes the same aircraft substitutions 
that are shown in the table above in the section on ``Phase-Out of 
Category B for Category C Aircraft.'' Total 12-year costs equal $14 
million with a present value of $9 million.

Benefits

    The benefits of noise reduction attributable to this rulemaking can 
be broadly categorized as use and non-use benefits. Use benefits are 
the benefits perceived by individuals from the direct

[[Page 69348]]

use of a resource such as hiking, rafting, or sightseeing. Non-use 
benefits are the benefits perceived by individuals from merely knowing 
that a resource is preserved in a given state. For example, GCNP 
clearly has value to people who have not visited the park, but take 
pleasure from the knowledge of its existence. It also has value to 
people who may wish to visit the Park at some future date. The non-use 
benefits attributable to this rulemaking have not been estimated but 
are described qualitatively. The use benefits of this rulemaking have 
been estimated and are presented below.
    The Final Rule revising SFAR 50-2 contains certain overflight 
restrictions. The benefits of those restrictions have been estimated 
and are reported in the Final Rule. The NPRM would further amend SFAR 
50-2 and the additional benefits are estimated here. The same 
methodology and some of the same data used to estimate benefits for the 
Final Rule are also used to estimate benefits in the NPRM.
    Economic studies have not been conducted specifically to estimate 
benefits for the NPRM. Benefits are, therefore, estimated for analogous 
situations combining value estimates from existing economic studies 
with site-specific information related to GCNP and other information. 
Certain criteria should be applied to ensure that appropriate studies 
are selected. Those criteria are:
     Selected economic studies must reasonably represent the 
resources to be valued in terms of physical characteristics, service 
flows, user characteristics, and available substitutes;
     Selected economic studies must be scientifically sound. 
Studies that are either published in a peer-reviewed academic journal 
or are conducted by a recognized university-associated researcher or 
established consulting firm are considered to be scientifically sound; 
and
     Selected economic studies must use appropriate valuation 
methodologies.
    The site-specific information used in the benefits estimation 
includes visitation data for GCNP and a visitor survey conducted to 
document the visitor impacts of aircraft noise within GCNP. The 
available visitation data for GCNP permits the categorization of 
visitors into the following groups: backcountry users, river users, and 
other visitors. ``Other visitors'' includes those sightseeing, 
picnicking, pleasure driving, etc. National Park Service estimates for 
the number of visitor-days in 1995 for these visitor groups are as 
follows:

                     Number of Visitor-Days in 1995                     
------------------------------------------------------------------------
                      Visitor group                        Visitor days 
------------------------------------------------------------------------
Backcountry.............................................         115,478
River...................................................         168,602
Other...................................................       5,517,720
                                                         ---------------
      Total.............................................       5,801,800
------------------------------------------------------------------------

    The GCNP visitor survey indicates that these different visitor 
groups are variously affected by aircraft noise (HBRS, Inc. and Harris 
Miller Miller & Hanson, Inc. 1993). This survey asked respondents to 
classify the interference of aircraft noise with their appreciation of 
the natural quiet of GCNP as either ``not at all,'' ``slightly,'' 
``moderately,'' ``very much,'' or ``extremely.'' The percent of 
visitors indicating these impacts is presented below by visitor group.

    Visitors Affected by Aircraft Noise in Grand Canyon National Park   
------------------------------------------------------------------------
                                           Back-                        
                                          country     River      Other  
                 Impact                  visitorsa  visitorsb   visitors
                                         (percent)  (percent)  (percent)
------------------------------------------------------------------------
Not At All.............................      41.0       45.5       76.0 
Slightly...............................      15.0       16.5       11.0 
Moderately.............................      13.5       10.0        4.0 
Very Much..............................      14.5       12.5        4.0 
Extremely..............................      16.0       15.5        5.0 
------------------------------------------------------------------------
a Average for Summer and Fall users.                                    
b Average for motor and oar users.                                      
Source: HBRS, Inc. and Harris Miller Miller & Hanson, Inc. 1993.        

    The economic studies selected for use in the benefit estimation are 
listed below. These studies value recreational activities in or near 
GCNP. All dollar amounts are indexed to 1995. The implicit price 
deflator for GDP was used to index all values (Survey of Current 
Business, March 1996).

                           Visitor-Day Values                           
------------------------------------------------------------------------
                                                               Consumer 
             Activity                      Study \4\         surplus per
                                                             visitor-day
------------------------------------------------------------------------
Hiking in Arizona................  Martin, Russell, and           $43.16
                                    Smith 1974.                         
Multi-Day Rafting in Grand Canyon  Boyle, Welsh, and Bishop       128.21
 Natl Park.                         1988.                               
Sightseeing in Bryce Canyon Natl   Haspel and Johnson 1982.        39.71
 Park.                                                                  
------------------------------------------------------------------------
\4\ Reported in Walsh, Johnson, and McKean 1988.                        

    Consumer surplus is the difference between the maximum amount a 
consumer is willing to pay and what the consumer actually pays. It is a 
measure of the increase in well-being gained by individuals through 
participation in recreational activities.
    It was assumed that these visitor-day values represent the value of 
participating in the indicated activities at GCNP absent any impacts 
from aircraft noise. It should be noted that these values potentially 
understate the value of participation absent any impacts from aircraft 
noise to the extent that they were estimated in conditions where 
aircraft noise was present.
    There is no economic study available that estimates the reduction 
in the value of participation that is attributable to the ``slightly,'' 
``moderately,'' ``very much,'' or ``extremely'' impacts described in 
the GCNP visitor survey. Therefore, the following reductions were 
assumed. The results of a sensitivity analysis using lower percentage 
reductions are reported below.

                Assumed Reductions in Visitor-Day Values                
------------------------------------------------------------------------
                                                               Reduction
                            Impact                             (percent)
------------------------------------------------------------------------
Slightly.....................................................        20 
Moderately...................................................        40 
Very Much....................................................        60 
Extremely....................................................        80 
------------------------------------------------------------------------

    The total lost value for each category was calculated as the 
product of the number of visitor-days, the proportion

[[Page 69349]]

of visitors affected by aircraft noise, the visitor-day value, and the 
assumed proportional reduction in the visitor-day value. For example 
the total lost value for river users that were moderately affected is 
the product of the number of river visitor-days (168,602), the 
proportion of river users that were moderately affected by aircraft 
noise (10.0 percent), the visitor-day value for river use ($128.21), 
and the assumed reduction in the visitor-day value given a moderate 
impact (40 percent).
    Based on the number of visitors to the park in each use category, 
these data and assumptions imply the following total lost values from 
all aircraft noise in 1995 as noted in the table below. Approximately 
58 percent of these benefits were estimated to be obtained by the final 
rule revising SFAR 50-2. That leaves approximately 42 percent of the 
total available for this NPRM.

                                Total Lost Value From All Aircraft Noise in 1995                                
----------------------------------------------------------------------------------------------------------------
                                                     Backcountry                                                
                       Impact                          visitors   River visitors  Other visitors       Total    
----------------------------------------------------------------------------------------------------------------
Slightly...........................................     $149,509        $716,677      $4,819,884      $5,686,070
Moderately.........................................      269,116         868,700       3,505,370       4,643,186
Very Much..........................................      433,576       1,628,812       5,258,055       7,320,443
Extremely..........................................      637,905       2,692,969       8,763,425      12,094,299
                                                    ------------------------------------------------------------
      Total........................................  ...........  ..............  ..............      29,743,998
----------------------------------------------------------------------------------------------------------------

    The benefit of the proposed rule is that portion of the total lost 
value that is associated with the resulting noise reduction. Aircraft 
noise modeling has produced a measures called Leq12, which is a 
non-linear form. Determining a linear measurement of noise reduction 
weighted by ground area over different levels requires calculation of 
the antilog of the contour levels. This process produces an estimated 
sound energy level that can be compared linearly over varying ground 
areas. The noise reduction results for this NPRM are presented below.
    Average linearized noise measure, weighted by the square miles over 
which different levels, are predicted to occur according to the 
following schedule:

------------------------------------------------------------------------
                                                                 Noise  
                Year                   No NPRM     With NPRM   reduction
                                                               (percent)
------------------------------------------------------------------------
1997...............................     1,268.33     1,277.70     -0.74 
2000...............................     1,268.33     1,087.83     14.23 
2008...............................     1,268.33       685.96     45.92 
------------------------------------------------------------------------

    The 45.92% noise reduction by the year 2008 corresponds to the 
finding in the environmental assessment of this proposed rule that 57.4 
percent of the GCNP area will have achieved natural quiet as defined by 
NPS.
    The indicated reduction in aircraft noise for each year was applied 
to the total lost value from all aircraft noise. Subtracted from that 
application is the amount applied as estimated benefits for the final 
rulemaking revising SFAR 50-2. That product yields the current use 
benefit for that year.
    Linear interpolation was used to estimate benefits between the 
years 1997 to 2000, and 2000 to 2008. A 3 percent discount rate was 
then applied to calculate the present value of use benefits over the 
ten year regulatory evaluation period. The economics literature 
supports a 3 percent discount rate for natural resource valuation 
(e.g., Freeman 1993). Recent Federal rulemakings also support a 3 
percent discount rate for natural resource valuation (61 FR 453; 61 FR 
20584). The total indicated benefits represent approximately 22 percent 
of the total benefits available. The resulting use benefit estimates 
are presented in the following table.

              Indicated Use Benefits of the Overflight NPRM             
------------------------------------------------------------------------
                                              Current                   
                   Year                        value      Present value 
------------------------------------------------------------------------
1997.....................................    $(106,234)       $(103,140)
1998.....................................      598,389          564,039 
1999.....................................    1,279,091        1,170,549 
2000.....................................    1,869,864        1,661,350 
2001.....................................    2,324,027        2,004,726 
2002.....................................    2,749,363        2,302,548 
2003.....................................    3,145,872        2,557,881 
2004.....................................    3,513,553        2,773,632 
2005.....................................    3,852,408        2,952,550 
2006.....................................    4,162,436        3,097,244 
2007.....................................    4,443,637        3,210,178 
2008.....................................    4,696,011        3,293,688 
                                          ------------------------------
      Total..............................                    25,485,244 
------------------------------------------------------------------------

    It is important to recognize significant uncertainties in this 
estimation. One uncertainty relates to the percentage reductions in 
visitor-day values that can be attributed to aircraft noise. It was 
assumed above that there is a 20 percent reduction for visitors 
affected ``slightly,'' a 40 percent reduction for visitors affected 
``moderately,'' a 60 percent reduction for visitors affected ``very 
much,'' and an 80 percent reduction for visitors affected 
``extremely.'' In recognition of the uncertainty surrounding this 
assumption, one-half of these percentage reductions were used to 
calculate an alternative benefit estimate. Additionally, in recognition 
of the discount rate recommended in OMB Circular A-94, alternative 
benefit estimates were calculated using a 7 percent discount rate. 
These alternative benefit estimates are presented below.

           Alternative Use Benefits Attributable to This NPRM           
                        [Present value, 12 years]                       
------------------------------------------------------------------------
 Visitor day value reduction assumption            Discount rate        
    (slightly, moderately, very much,    -------------------------------
               extremely)                    3 percent       7 percent  
------------------------------------------------------------------------
20, 40, 60, 80..........................     $25,485,000     $18,795,000
10, 20, 30, 40..........................      12,979,473       9,572,011
------------------------------------------------------------------------

    The FAA and the NPS believe that the true representation of 
benefits from the proposed rule are reflected by the three percent 
discount rate and the visitor day value reduction of 20%, 40%, 60%, 80% 
with the resulting value of 25,485,000, and that value is used to 
represent the use benefits of this proposal.
    In addition to these use benefits, this rulemaking would likely 
generate non-use benefits. Although the FAA and the NPS have not 
attempted to estimate the magnitude of these benefits, non-use benefits 
have been documented and estimated in the general proximity of the 
Grand Canyon. In a study relating to the operation of Glen Canyon Dam 
(Hagler Bailly Consulting 1995), annual non-use benefits in a range 
from $2,286.4 million to $3,442.2 million were estimated based on a 
national

[[Page 69350]]

survey. No attempt has been made to relate these non-use benefit 
estimates to the potential non-use benefits of aircraft noise reduction 
that would occur as a result of this proposal. However, these estimates 
do suggest that potentially significant non-use benefits can be 
attributed to this proposed rulemaking.

National Canyon Corridor

    The GCNP Final Rule, which is being simultaneously promulgated with 
this proposal, will expand one of the park's flight free zones and 
eliminate the Blue 1 route. The NPRM would reopen that route 
(redesignated as Blue 1A) to airtour operators, provided they use 
Category C aircraft.
    The FAA estimates that the revenues potentially lost from 
eliminating the old Blue 1 route, and included as an average cost of 
$2.3 million per year in the GCNP Final Rule, would be increasingly 
recovered throughout the period 1997-2008 as a result of the proposal 
as operators phase out Categories A and B aircraft and replace them 
with Category C aircraft.\5\ In 1997, the FAA estimates that about 28 
percent of the flights between Las Vegas and Tusayan would be conducted 
using Category C aircraft and would, therefore, use the new Blue 1A 
route. The remaining air tour flights between Las Vegas and Tusayan 
would not include a flight through the Blue 1A route and would have a 
reduced fare. This percentage would increase each year as Categories A 
and B aircraft are phased out. By 2001 approximately half of the 
flights between Las Vegas and Tusayan will be conducted using Category 
C aircraft, and therefore, fly the Blue 1A route. By 2008, the proposed 
deadline for complete phase out for Categories A and B aircraft, all 
flights would be conducted using Category C aircraft.
---------------------------------------------------------------------------

    \5\ See Notice of Availability of Proposed Air Tour Routes 
published in the Federal Register with this NPRM.

                        Reduction in Revenue Loss                       
------------------------------------------------------------------------
                  Year                     Current value   Present value
------------------------------------------------------------------------
1997....................................        $566,259        $529,214
1998....................................         663,459         579,491
1999....................................         754,727         616,082
2000....................................         778,156         593,651
2001....................................       1,180,220         841,480
2002....................................       1,616,147       1,076,907
2003....................................       1,987,803       1,237,904
2004....................................       2,365,380       1,376,673
2005....................................       2,447,181       1,331,104
2006....................................       2,532,784       1,287,539
2007....................................       2,757,791       1,310,207
2008....................................       2,848,798       1,264,900
                                         -------------------------------
Totals..................................      20,498,704      12,045,152
------------------------------------------------------------------------

    The FAA estimates that the recovered lost revenue (net of variable 
operating costs) attributable to the proposed rule would increase from 
$556,000 in 1997 to $2.8 million in 2008. The current values and seven 
percent discounted values are shown in the table above.
    The FAA estimated natural resource benefits, discounted at three 
percent, for the 12-year period 1997-2008 to be $25.5 million. The FAA 
also estimated non-resource benefits (increased airtour operator 
profits), discounted at seven percent, for the 12-year period to be 
$12.0 million. The combined total benefit of this proposal, therefore, 
is estimated to be $37.5 million.

Summary of Costs and Benefits

    The total quantified costs of this proposal to establish noise 
limitations for certain aircraft operated in the vicinity of the GCNP 
are estimated to be $172.6 million undiscounted or $96.7 million 
discounted to present value.
    The quantified benefits, including noise reduction and use of the 
Blue 1A scenic route, are estimated to be $47.4 million undiscounted 
and $37.5 million discounted to present value. In addition to 
quantified benefits, there are substantial unquantified benefits as 
discussed above.
    However, estimates of costs and benefits of the proposal were made 
primarily as an aid in evaluating the economic impacts of a phase-out 
that the FAA believes is necessary to obtain substantial reductions in 
aircraft noise in GCNP. The benefits justifying the restoration of 
natural quiet to the park have already been established by the American 
public, and that determination was carried out by their elected 
representatives in enactment of the law directing that natural quiet be 
restored. Based on that direction and the quantified and unquantified 
costs and benefits contained in this analysis, the FAA finds this 
proposal to be cost beneficial.

Alternatives

    As explained in the Introduction of this regulatory evaluation, the 
proposed rule has been deemed ``significant'' due to its high cost and 
the impact it would have on small entities. As a result, the FAA has 
identified and considered alternatives to the proposed rule. 
Alternative 1 is the proposed rule. Alternative 2 is to not undertake 
rulemaking at this time beyond the final rule being implemented 
simultaneously with this proposal. Alternative 3 is the same as 
Alternative 1, but with no interim phase-out of Category B aircraft. 
Operators would presumably hold on to their aircraft until the last 
minute and replace them at the end of 2000 or 2008 depending on what 
type of aircraft they had.

Cost of Alternatives

    A side-by-side cost comparison of Alternatives 1 and 3 is presented 
in the table below. Alternative 2 would have no cost and is therefore 
not included. Alternatives 1 and 3 have the same total cost because the 
same type and number of aircraft would be replaced under both 
alternatives. However, operators would have a longer time in which to 
comply under Alternative 3 than under Alternative 1. Therefore, the 
present value of the cost of that compliance would be less.

                                     Cost Comparison of Alternatives 1 and 3                                    
----------------------------------------------------------------------------------------------------------------
                                                                    Alternative 1             Alternative 3     
                                                             ---------------------------------------------------
                       Cost categories                                       Present                   Present  
                                                               Total cost     value      Total cost     value   
----------------------------------------------------------------------------------------------------------------
Certified Noise Efficiency Level............................        $0.08        $0.07        $0.08        $0.07
Phase Out Category A to B...................................        74.33        42.06        74.33        33.99
Phase Out Category B to A...................................        60.92        33.49        60.92        27.05
Non-Addition Category A.....................................        21.76        11.87        21.76         9.68

[[Page 69351]]

                                                                                                                
Non-Addition Category B.....................................        14.07         8.42        14.07         7.07
                                                             ---------------------------------------------------
      Total.................................................       171.16        95.91       171.16        77.86
----------------------------------------------------------------------------------------------------------------

Benefits of Alternatives

    The benefits of Alternative 1 have already been estimated in the 
Benefits section above. There are no benefits to Alternative 2 since it 
merely maintains the status quo.
    Alternative 3 would require the same conversion as that required in 
alternative 1, except that phase-out would not be required. As with the 
cost analysis, this benefits analysis assumes that all operators of 
Category A aircraft would wait until the year 2000 to convert their 
aircraft to Category B. Also, it is assumed that operators would wait 
until the year 2008 to convert their Category B aircraft to Category C 
aircraft because there would be no mandatory phase-out of Category B 
aircraft before 2008.
    As with Alternative 1, the indicated reduction in aircraft noise 
for each year was applied to the total lost value from all aircraft 
noise. However, the indicated reduction remained constant at -0.74 
percent from 1997 to 2000 and 14.23 percent from the years 2000 to 
2008. In the year 2008, it is assumed the noise reduction reaches the 
indicated 45.92 percent. Subtracted from the application is the amount 
applied as estimated benefits for the final rule making revising SFAR 
50-2. That product yields the current use benefit for that year. The 
annual current use benefits are presented in the following table two 
tables.

      Alternative 3.--Indicated Use Benefits of the Overflight NPRM     
------------------------------------------------------------------------
                                              Current    Present value 3
                   Year                        value         percent    
------------------------------------------------------------------------
1997.....................................    $(106,234)       $(103,140)
1998.....................................     (103,931)         (97,965)
1999.....................................     (102,204)         (93,531)
2000.....................................    1,869,864        1,661,350 
2001.....................................    1,818,071        1,568,284 
2002.....................................    1,766,278        1.479,230 
2003.....................................    1,714,486        1,394,034 
2004.....................................    1,662,693        1,312,545 
2005.....................................    1,610,901        1,234,621 
2006.....................................    1,559,108        1,160,123 
2007.....................................    1,507,315        1,088,917 
2008.....................................    4,696,011        3,293,688 
                                          ------------------------------
      Total..............................  ............      13,898,156 
------------------------------------------------------------------------

    The benefits of restoring the Blue 1A route for Alternatives 1, 2, 
and 3 are the same. As discussed above in the Benefits section, the 
benefits of implementing this route are $12 million over the 12-year 
period. When combined with the $13.9 million natural-resource benefits, 
the total present value benefits of Alternative 3 would be $25.9 
million.
    The following table compares the costs and benefits of the three 
proposals. The FAA has rejected Alternative 2 because it relies solely 
on the final rule issued concurrently with this NPFM to achieve the 
substantial restoration of natural quiet mandated by Congress. The 
NPS's definition of substantial restoration is the situation in which 
50 percent or more of the Park is free of aircraft noise at least 75 
percent of the time. Based on noise estimates contained in the 
environmental assessment associated with this proposal, the final rule 
would only marginally achieve these goals in 1997, and would begin to 
fall below the goal as activity increases in the future. The FAA 
believes that substantial further reductions in aircraft noise could be 
achieved by taking advantage of the advanced technology incorporated 
into quieter aircraft now available. Therefore, the agency rejects 
Alternative 2 in favor of one that is estimated to meet or exceed NPS 
standards for the immediate future.
    The FAA has rejected Alternative 3 because, while similar to the 
proposal, it would impose no phase-out schedule for Category B aircraft 
beyond the requirement that they discontinue operations by December 31, 
2008. Imposing no phase-out schedule was considered as a way to provide 
operators more flexibility in transitioning from Category B to Category 
C aircraft. A cost analysis of this alternative, based on the 
assumption that operators would delay phasing out Category B aircraft 
as long as possible, indicated that there would be a cost savings to 
operators only in that investment in some Category C aircraft would be 
delayed. On the other hand, the benefits of less aircraft noise in the 
Park would also be less during the transition period. Further, if 
operators actually did delay the phase-out until the last year, they 
would probably not be able to find suitable replacement aircraft or 
would have some other reason for requesting an extension of time. The 
FAA's experience in other rulemaking actions requiring a transition is 
that most operators do not wait until the deadline. Instead, they 
develop their own transition schedules. Based on the above, the FAA 
decided that establishing a transition schedule as contained the 
proposal would provide for a phase-out that will assure early benefits 
and can be effectively monitored. Therefore, the Agency rejects 
Alternative 3.

               Alternatives Costs and Benefits Comparison               
                               [Millions]                               
------------------------------------------------------------------------
                                             Present    Present  Benefit
                                              value      value     cost 
                                              costs    benefits   ratio 
------------------------------------------------------------------------
Alternative 1.............................     $95.91     $37.5      .39
Alternative 2.............................        0.0       0.0      N/A
Alternative 3.............................      77.86      25.9      .33
------------------------------------------------------------------------

Initial Regulatory Flexibility Analysis

    By both law and executive order, Federal regulatory agencies are 
required to consider the impact of proposed regulations on small 
entities. Executive Order 12866 ``Regulatory Planning and Review'', 
dated September 30, 1993, states that:
    Each agency shall tailor its regulations to impose the least burden 
on society, including individuals, businesses of different sizes, and 
other entities (including small communities and governmental entities), 
consistent with obtaining the regulatory objectives, taking into 
account, among other things, and to the extent practicable, the costs 
of cumulative regulations.
    The 1980 ``Regulatory Flexibility Act'' (RFA) requires Federal 
agencies to prepare an initial regulatory flexibility analysis of any 
notice of proposed rulemaking that will have a significant economic 
impact on a substantial number of small entities. The definition

[[Page 69352]]

of small entities and guidance material for making determinations 
required by the RFA are contained in the Federal Register [47 FR 32825, 
July 29, 1982]. Federal Aviation Administration (FAA) order 2100.14A 
outlined the agency's procedures and criteria for implementing the RFA.
    With respect to this proposed rule, a ``small entity'' is a 
commercial sightseeing operator that for all practical purposes owns or 
operates nine or fewer aircraft. A significant economic impact on a 
small entity is defined as an annualized net compliance cost to such a 
small commercial sightseeing operator. In the case of scheduled 
operators of aircraft for hire having less than 60 passenger seats, a 
``significant economic impact'' or cost threshold, is defined as an 
annualized net compliance cost level that exceeds $69,800; for 
unscheduled operators the threshold is $4,900. A substantial number of 
small entities is defined as a number that is more than one-third of 
the small commercial sightseeing operators (but not less than eleven 
operators) subject to the proposed rule.
    The Federal Aviation Administration has determined that this 
proposal could have a significant economic impact on all commercial 
sightseeing operators conducting flights within Grand Canyon National 
Park and therefore has prepared this initial regulatory flexibility 
analysis. The analysis, structured in accordance with section 603 of 
the RFA, requires the following:
    1. Why FAA action is being considered.
    2. Statement of the objectives and legal basis for the proposed 
rule.
    3. Description of and estimated number of small entities affected.
    4. Projected reporting, recordkeeping, and other compliance 
requirements of the proposed rule.
    5. Any relevant Federal rules which may duplicate, overlap or 
conflict with the proposed rule.
    Why FAA Action is Being Considered: The proposal to establish noise 
limitations for certain aircraft operations in the vicinity of the 
Grand Canyon National Park stems from the need to further reduce the 
impact of aircraft noise on the park environment and assist the 
National Park Service in achieving its statutory mandate imposed by 
Public Law 100-91 to provide for the substantial restoration of natural 
quiet and experience in the Grand Canyon National Park.
    Statement of the Objectives and Legal Basis for the Proposed Rule: 
In 1987, Congress enacted Public Law (Pub. L.) 100-91, commonly known 
as the National Parks Overflights Act (the Act). The Act stated, in 
part, that noise associated with aircraft overflights at GCNP was 
causing a ``significant adverse effect on the natural quiet and 
experience of the park and current aircraft operations at the Grand 
Canyon National Park have raised serious concerns regarding public 
safety, including concerns regarding the safety of park users.''
    Public Law 100-91 requires the Department of the Interior to submit 
to the FAA recommendations to protect resources in the Grand Canyon 
from adverse impacts associated with aircraft overflights. The law 
mandated that the recommendations: (1) Provide for substantial 
restoration of the natural quiet and experience of the park and 
protection of public health and safety from adverse effects associated 
with aircraft overflights; (2) with limited exceptions, prohibit the 
flight of aircraft below the rim of the canyon; and (3) designate 
flight-free zones except for purposes of administration and emergency 
operations. In December of 1987, the DOT transmitted its ``Grand Canyon 
Aircraft Management recommendations'' to the FAA, which included both 
rulemaking and nonrulemaking actions.
    On May 27, 1988, the FAA issued SFAR No. 50-2 revising the 
procedures for operation of aircraft in airspace above the Grand Canyon 
(53 FR 20264, June 2, 1988). The SFAR, among other things, limited the 
areas for aircraft operations by establishing special flight routes for 
commercial operators. Since that time, a substantial amount of public 
debate has taken place regarding the effect of aircraft noise on the 
Grand Canyon's environment. The debate and the objective of the 
proposal is more thoroughly discussed in the preamble of this proposed 
rulemaking.
    On June 15, 1995, the FAA published a final rule that extended the 
provisions of SFAR No. 50-2 to June 15, 1997 (60 FR 31608). This action 
allowed the FAA sufficient time to review thoroughly the NPS 
recommendations as to their impact on the safety of air traffic over 
GCNP, and to initiate and complete any appropriate rulemaking action.
    On September 16-20, 1996, in Scottsdale, Arizona, and Las Vegas, 
Nevada, the FAA held public meetings to obtain additional comment on 
the NPRM. entitled ``Special Flight Rules in the Vicinity of Grand 
Canyon National Park,'' and on the draft environmental assessment that 
accompanied that proposal. Comments and the transcripts of these 
meetings have been placed in rulemaking docket No. 28537 for Notice 96-
11.
    Description and Estimated Number of Small Entities Affected: The 
proposed rulemaking will affect commercial sightseeing operators 
conducting flights over the Grand Canyon National Park under 14 CFR 
part 135. These commercial operators provide sightseeing tours of the 
Grand Canyon over the four flight zones established by SFAR 50-2. FAA 
data shows that in 1995, there were 26 potentially affected small 
commercial sightseeing operators, each owning, but not necessarily 
operating 9 or fewer aircraft. These operators owned a total of 70 
aircraft and the average fleet consisted of about 3 airplanes. The FAA 
estimated that 26 operators, which are also small entities, will be 
impacted by the proposed rules.
    Projected Reporting, Recordkeeping, and Other Compliance 
Requirements of the Proposed Rule: The proposal would not require 
affected small commercial sightseeing operators to maintain and report 
additional information.
    The proposed rule would require that operators phaseout noisier 
aircraft. The proposed rule would allow B category aircraft to replace 
phased out A category aircraft.
    Any Relevant Federal Rules Which May Duplicate, Overlap or Conflict 
with the Proposed Rule: There are no relevant Federal rules which will 
duplicate, overlap or conflict with the proposed rule.

Cost of Compliance to Small Entities

    The FAA has determined that four aircraft models currently 
operating in GCNP predate FAA noise standards and therefore do not have 
certificated noise levels. To obtain a level to use to compare with the 
Grand Canyon National Park noise efficiency limit may require analysis 
or a measurement test. Only four aircraft total operating at the Grand 
Canyon National Park (CE 180, CE 206, PA-28-180, and BT-206-B), do not 
have certificated noise levels. The cost per analysis or test is 
$18,750 or $2670 annualized at 7 percent over 10 years. In no situation 
would a substantial number of small operators be significantly impacted 
because the annualized cost is below even the lowest threshold for 
unscheduled operators and no operator owns more than one of these 
aircraft.
    To calculate the annualized cost impact on a small operator of the 
phaseout schedule, the FAA in the regulatory evaluation determined the 
cost impact on operators by aircraft type. That is, given the fleet mix 
of a particular operator, the FAA calculated the cost of replacing a 
given noncompliant aircraft with a complaint one. The incremental 
annualized fixed

[[Page 69353]]

and variable costs of replacing noncompliant aircraft with compliant 
aircraft is shown in the following table.
    The FAA has determined that, after multiplying the annualized 
incremental cost per aircraft type by the number of aircraft that 
operators currently own/or operate, 23 small entities would be 
significantly impacted under the guidelines outlined earlier. 
Therefore, a substantial number of operators affected by this proposed 
requirement (which is more than one-third of all GCNP commercial 
sightseeing operators) would incur a significant cost impact (See table 
in full regulatory evaluation.).

Description of Alternative Actions

    Section 603(c) of the RFA requires that each initial regulatory 
flexibility analysis contain a description of any feasible alternatives 
to the proposed rule that would accomplish the stated objectives of 
applicable statutes and that minimizes any significant economic impact 
of the proposed rule on small entities.
    The FAA and the NPS have made extensive efforts, including the 
public meeting at Flagstaff, to determine the optimal action to reduce 
aircraft noise and provide for the substantial restoration of natural 
quiet in the GCNP. In addition to this proposed rule's phaseout of 
operations of certain types of aircraft, the FAA and the NPS considered 
two other alternatives, described below.

Alternative Two

    Under this alternative, the FAA would not issue an NPRM phasing out 
noisier aircraft at this time. Instead, the FAA would adopt an approach 
that would ``wait-and-see'' the extent to which promulgation of part 
93, subpart U--Special Flight Rules in the Vicinity of Grand Canyon 
National Park, AZ, would reduce aircraft noise and provide for 
substantial restoration of natural quiet in the GCNP. Promulgation of 
part 93, subpart U, issued concurrently with this NPRM, will reduce 
aircraft noise in the park by establishing new and modifying existing 
flight-free zones and enlarging the Special Flight Rules Area.
    Quieter, generally larger, aircraft are available, however, that 
would restore more of the natural quiet in the park. Based on an 
extensive review of all current information available, the FAA has 
concluded that the use of these quieter aircraft is necessary to 
reducing noise substantially more toward natural quiet, and that 
initiating a phase-out of noisier aircraft immediately will 
significantly contribute to achieving natural quiet goals. Therefore, 
the FAA rejects this alternative.

Alternative Three

    Under this alternative, Category A aircraft would be banned after 
December 31, 2000, and Category B aircraft would be banned after 
December 31, 2008, just as in the proposal, but an interim compliance 
schedule would not be implemented to phase out Category B aircraft 
between 2001 and 2008. Although operators of Category B aircraft could 
replace their aircraft with Category C aircraft before the end of 2008, 
there would be no requirement to do so.
    This alternative could postpone a further reduction in aircraft 
noise and postpone restoration of the natural quiet in the park during 
the period 2001-2008. Therefore, the FAA rejects this alternative.

International Trade Impact Assessment

    The FAA has determined that the proposed rulemaking will not affect 
non-U.S. operators of foreign aircraft operating outside the United 
States or U.S. trade. It could however, have an impact on commercial 
sightseeing at GCNP, much of which is foreign.
    The United States Air Tour Association estimates that 60 percent of 
all commercial sightseeing tourists in the United States are foreign. 
The Las Vegas FSDO, however, believes this estimate to be considerably 
higher at GCNP, perhaps as high as 90 percent. The FAA cannot put a 
dollar value on the portion of the potential loss in commercial 
sightseeing revenue associated with the loss of foreign tour dollars.

Federalism Implications

    The regulations herein would not have substantial direct effects on 
the states, on the relationship between the national government and the 
states, or on the distribution of power and responsibilities among the 
various levels of government. Therefore, in accordance with Executive 
Order 12866, it is determined that this rule does not have sufficient 
federalism implications to warrant the preparation of a Federalism 
Assessment.

Paperwork Reduction Act

    In accordance with the Paperwork Reduction Act of 1995 (Pub. L. 
104-13), there are no requirements for information collection 
associated with the proposed regulation.

Conclusion

    For the reasons set forth above, the FAA has determined that this 
proposed rule is a significant regulatory action under Executive Order 
12866. In addition, the FAA certifies that this proposal would have a 
significant economic impact, positive or negative, on a substantial 
number of small entities under the criteria of the Regulatory 
Flexibility Act. This proposed rule is considered significant under DOT 
Regulatory Policies and Procedures.

List of Subjects in 14 CFR Part 93

    Air traffic control, Airports, Navigation (Air), Reporting and 
recordkeeping requirements.

The Proposed Amendment

    For the reasons set forth above, the Federal Aviation 
Administration proposes to amend 14 CFR part 93 as follows:

PART 93--SPECIAL AIR TRAFFIC RULES AND AIRPORT TRAFFIC PATTERNS

    1. The authority citation for part 93 continues to read as follows:

    Authority: 49 U.S.C. 106(g), 40103, 40106, 40109, 40113, 44502, 
44514, 44701, 44719, 46301.


Sec. 93.305  [Amended]

    2. Section 93.305 is amended by adding before the period at the end 
of paragraph (c) the words: ``and not including the following airspace 
designated as the National Canyon corridor: that airspace one mile on 
either side of a line extending from Lat. 36 deg.08'43'' Long. 
113 deg.09'19'' to Lat. 36 deg.15'30'', Long. 112 deg.51'07'' to Lat. 
36 deg.14'38'', Long. 112 deg.45'56'' to Lat. 36 deg.18'17'', Long. 
112 deg.42'22'' to Lat. 36 deg.17'49'', Long. 112 deg.39'54'' to Lat. 
36 deg.12'36'', Long. 112 deg.34'120'' to Lat. 36 deg.08'12'', Long. 
112 deg.34'36'' then back to the Blue One Direct Route at Havatagvitch 
Canyon Point.
    3. Section 93.306 is added to read as follows:


Sec. 93.306  Operation of GCNP Category C Aircraft in National Canyon 
Corridor.

    No person may operate an aircraft within the National Canyon 
Corridor within the Special Flight Rules Area unless the aircraft is a 
commercial sightseeing operation aircraft that meets the GCNP Category 
C aircraft standard, as defined in Sec. 93.319.


Sec. 93.307  [Amended]

    4. Section 93.307 is amended by adding at the end of the section 
after (b)(2)(iii) a new paragraph (b)(3) to read as follows:
* * * * *
    (b) * * *
    (3) GCNP Category C aircraft in the National Canyon Corridor. 7,500 
feet MSL.

[[Page 69354]]

Sec. 93.316  [Amended]

    5. Section 93.316 is amended by removing paragraph (b) and removing 
the paragraph designation ``(a)'' from the remaining paragraph.
    6. Section 93.319 is added to read as follows:


Sec. 93.319  Noise limitations for commercial sightseeing flights.

    (a) Definitions. For the purpose of this section only--
    Base level for Category A aircraft means the total number of 
category A aircraft listed on a certificate holder's operations 
specifications on December 31, 1996, and for Category B aircraft means 
the total number of Category B aircraft listed on a certificate 
holder's operations specifications on December 31, 2000, for use in 
commercial sightseeing operations within the SFRA.
    GCNP Category A aircraft means an aircraft that has not been shown 
to comply with the GCNP Category B or GCNP Category C noise limit in 
appendix B of this part.
    GCNP Category B aircraft means an aircraft that has been shown to 
comply with the GCNP Category B noise limit in appendix B of this part, 
but not the GCNP Category C noise limit in appendix B of this part.
    GCNP Category C aircraft means an aircraft that has been shown to 
comply with the GCNP Category C noise limit in appendix B of this part.
    New Entrant Operator means any person that was not authorized to 
conduct commercial sightseeing operations within the SFRA as of 
December 31, 1996.
    (b) GCNP Category A Aircraft. After [Effective date of final rule], 
no certificate holder may operate a greater number of GCNP Category A 
aircraft in commercial sightseeing operations within the SFRA than the 
number of aircraft listed on that certificate holder's operations 
specifications on December 31, 1996, for use in commercial sightseeing 
operations within the SFRA. After December 31, 2000, no certificate 
holder may operate a GCNP Category A aircraft in commercial sightseeing 
operations within the SFRA.
    (c) GCNP Category B Aircraft. (1) After [Effective date of final 
rule], no certificate holder may operate a greater number of GCNP 
Category B aircraft in commercial sightseeing operations within the 
SFRA than the number of aircraft listed on that certificate holder's 
operations specifications on December 31, 1996, for use in commercial 
sightseeing operations within the SFRA, unless the aircraft was added 
to the certificate holder's operations specifications after December 
31, 1996, and on or before December 31, 2000, as a replacement for a 
GCNP Category A aircraft that was listed on that certificate holder's 
operations specifications on December 31, 1996, for use in commercial 
sightseeing operations within the SFRA.
    (2) After December 31, 2002, no certificate holder may operate more 
than 75 percent of the base level number of GCNP Category B aircraft in 
commercial sightseeing operations within the SFRA. Calculations 
resulting in fractions may be rounded to permit the continued operation 
of the next whole number of Category B aircraft.
    (3) After December 31, 2004, no certificate holder may operate more 
than 50 percent of the base level number of GCNP Category B aircraft. 
Calculations resulting in fractions may be rounded to permit the 
continued operation of the next whole number of Category B aircraft.
    (4) After December 31, 2006, no certificate holder may operate more 
than 25 percent of the base level number of GCNP Category B aircraft. 
Calculations resulting in fractions may be rounded to permit the 
continued operation of the next whole number of Category B aircraft.
    (5) After December 31, 2008, no certificate holder may operate a 
GCNP Category B aircraft in commercial sightseeing operations within 
the SFRA.
    (d) GCNP Category C Aircraft. Except for GCNP Category B aircraft 
added to the certificate holder's operations specifications as a 
replacement aircraft as authorized in paragraph (c)(1) of this section, 
no certificate holder may add an aircraft to its operations 
specifications for use in commercial sightseeing operations within the 
Special Flight Rules Area unless the aircraft is a GCNP Category C 
aircraft.
    (e) New entrant operators. After [insert effective date of final 
rule], no new entrant operator may conduct commercial sightseeing 
operations within the SFRA unless the aircraft used in those operations 
is a GCNP Category C aircraft.
    7. Appendix B is added to part 93 to read as follows:

Appendix B--GCNP Aircraft Noise Limits

    This appendix contains procedures for determining GCNP aircraft 
noise limits for each aircraft subject to Sec. 93.319 determined 
during the noise certification process as prescribed under part 36 
of this chapter. Where no certificated noise level is available, an 
alternative measurement procedure may be approved by the 
Administrator.

1. GCNP Category B Noise Limit

    A. For helicopters with a flyover noise level obtained in 
accordance with the measurement procedures prescribed in Appendix H 
of 14 CFR part 36, the limit is 84 dB for helicopters having 2 or 
fewer passenger seats, increasing at 3 decibels per doubling of the 
number of passenger seats for helicopters having 3 or more passenger 
seats. The limit at number of passenger seats of 3 or more can be 
calculated by the formula:

EPNL(H-Cat. B)=84 +101og (# PAX seats/2) dB

    B. For helicopters with a flyover noise level obtained in 
accordance wit the measurement procedures prescribed in Appendix J 
of 14 CFR part 36, the limit is 81 dB for helicopters having 2 or 
fewer passenger seats, increasing at 3 decibels per doubling of the 
number of passenger seats for helicopters having 3 or more passenger 
seats. The limit at number of passenger seats of 3 or more can be 
calculated by the formula;

SEL(J-Cat. B)=81 +10log(# PAX seats/2) dB

    C. For propeller-driven airplanes with a measured flyover noise 
level obtained in accordance with the measurement procedures 
prescribed in Appendix F of 14 CFR part 36 without the performance 
correction defined in Sec. F35.201(c), the limit is 73 dB for 
airplanes having 2 or fewer passenger seats, increasing at 3 
decibels per doubling of the number of passenger seats for airplanes 
having 3 or more passenger seats. The limit at number of passenger 
seats of 3 or more can be calculated by the formula:

LAmax (F-Cat. B)=73 +101og(# PAX seats/2) dB

    D. In the event that a flyover noise level is not available in 
accordance with Appendix F of 14 CFR part 36, the noise limit for 
propeller-driven airplanes with a takeoff noise level obtained in 
accordance with the measurement procedures prescribed in Appendix G 
is 78 dB for airplanes having 2 or fewer passenger seats, increasing 
at 3 decibels per doubling of the number of passenger seats for 
airplanes having 3 or more passenger seats. The limit at number of 
passenger seats of 3 or more can be calculated by the formula:

LAmax(G-Cat. B)=78+10log (# PAX seats/2) dB

2. GCNP Category C Noise Limit

    A. For helicopters with a flyover noise level obtained in 
accordance with the measurement procedures prescribed in Appendix H 
of 14 CFR part 36, the limit is 80 dB for helicopters having 2 or 
fewer passenger seats, increasing at 3 decibels per doubling of the 
number of passenger seats for helicopters having 3 or more passenger 
seats. The limit at number of passenger seats of 3 or more can be 
calculated by the formula:

EPNL(H-Cat. C)=80+10log (# PAX seats/2) dB

    B. For helicopters with a flyover noise level obtained in 
accordance with the measurement procedures prescribed in Appendix J 
of 14 CFR part 36, the limit is 77 dB for helicopters having 2 or 
fewer passenger seats, increasing at 3 decibels per doubling of the 
number of passenger seats for helicopters having 3 or more passenger 
seats. The limit at number of passenger seats of 3 or more can be 
calculated by the formula:

SEL(J-Cat. C)=77+10log (# PAX seats/2) dB


[[Page 69355]]


    C. For propeller-driven airplanes with a measured flyover noise 
level obtained in accordance with the measurement procedures 
prescribed in Appendix F of 14 CFR part 36 without the performance 
correction defined in Sec. F35.201(c), the limit is 69 dB for 
airplanes having 2 or fewer passenger seats, increasing at 3 
decibels per doubling of the number of passenger seats for airplanes 
having 3 or more passenger seats. The limit at number of passenger 
seats of 3 or more can be calculated by the formula:

LAmax(F-Cat. C)=69+10log (# PAX seats/2) dB

    D. In the event that a flyover noise level is not available in 
accordance with Appendix F of 14 CFR part 36, the noise limit for 
propeller-driven airplanes with a takeoff noise level obtained in 
accordance with the measurement procedures prescribed in Appendix G 
is 74 dB for airplanes having 2 or fewer passenger seats, increasing 
at 3 decibels per doubling of the number of passenger seats for 
airplanes having 3 or more passenger seats. The limit at number of 
passenger seats of 3 or more can be calculated by the formula:

LAmax(G-Cat. C)=74+10log (# PAX seats/2) dB

    Issued in Washington, DC, on December 24, 1996.
James D. Erickson,
Director, Office of Environment and Energy.
[FR Doc. 96-33145 Filed 12-30-96; 8:45 am]
BILLING CODE 4910-13-M