[Federal Register Volume 62, Number 151 (Wednesday, August 6, 1997)]
[Rules and Regulations]
[Pages 42364-42374]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-20641]
[[Page 42363]]
_______________________________________________________________________
Part IV
Department of Transportation
_______________________________________________________________________
Federal Aviation Administration
_______________________________________________________________________
14 CFR Part 135
Commercial Passenger-Carrying Operations in Single-Engine Aircraft
Under Instrument Flight Rules; Final Rule
Federal Register / Vol. 62, No. 151 / Wednesday, August 6, 1997 /
Rules and Regulations
[[Page 42364]]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 135
[Docket No. 28743; Amendment No. 135-70]
RIN 2120-AG22
Commercial Passenger-Carrying Operations in Single-Engine
Aircraft Under Instrument Flight Rules
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule.
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SUMMARY: The Federal Aviation Administration (FAA) is amending the
conditions and limitations in part 135 for instrument flight rule
(IFR), passenger-carrying operations in single-engine aircraft. The
rule will expand the passenger-carrying provisions of the current rule,
add equipment requirements, as well as maintenance requirements to
monitor engine reliability, and remove the limited IFR provisions of
the existing rule for both single and multi-engine aircraft. Visual
flight rules (VFR) flight into instrument meteorological conditions
(IMC) is the most significant cause of fatal accidents in Alaska and is
a serious problem for single-engine aircraft nationally. This action
will increase the safety of single-engine, passenger-carrying
operations by allowing planned instrument flight in the IFR system and
by imposing certain other conditions and limitations.
DATEs: The rule is effective May 3, 1998, except for SFAR No. 81.
Pending OMB clearance on the paperwork requirements, SFAR No. 81 is not
effective until the FAA publishes in the Federal Register a document
specifying the effective date. Comments on the clarification of
Secs. 135.163(f)(2), 135.411(c), and/or 135.421 (c) and (d), including
the paperwork requirements, must be received on or before September 5,
1997.
ADDRESSES: Comments on the clarification of sections 135.163(f)(2),
135.411(c), and/or 135.421 (c) and (d), including the paperwork
requirements, should be submitted to: Federal Aviation Administration,
Office of the Chief Counsel, Attn: Rules Docket (AGC-200), Room 915-G,
Docket No. 28743, 800 Independence Ave., SW, Washington, DC 20591.
FOR FURTHER INFORMATION CONTACT: Ms. Katherine Hakala, Flight Standards
Service, Federal Aviation Administration, 800 Independence Ave., SW,
Washington, DC 20591, (202) 267-8166/3760.
SUPPLEMENTARY INFORMATION:
Availability of Final Rule
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 (703) 321-
3339), the Federal Register's electronic bulletin board service (202)
512-1661), or the FAA's Aviation Rulemaking Advisory Committee Bulletin
Board service ((800) 322-2722 or (202) 267-5948). Internet users may
reach the FAA's web page at http://www.faa.gov or the Federal
Register's web page a http://www.access.gpo.gov/su__docs for access to
recently published rulemaking documents.
Any person may obtain a copy of this final rule by submitting a
request to the Federal Aviation Administration, Office of Rulemaking,
ARM-1, 800 Independence Ave, SW, Washington, DC 20591, or by calling
(202) 267-9677. Communications must identify the amendment number or
docket number of this final rule.
Persons interested in being placed on the mailing list for future
rules should request from the above office a copy of Advisory Circular
No. 11-2A, Notice of Proposed Rulemaking Distribution System, which
describes the application procedure.
I. Background
Prior to October 10, 1978, passenger-carrying, single-engine
instrument flight rule (SEIFR) operations were permitted if an aircraft
could descend to visual flight rules (VFR) conditions in the event of
an engine failure. This provision allowed operations in instrument
meteorological conditions (IMC) or over-the-top of a ceiling, as long
as VFR conditions existed below that ceiling (i.e., a buffer zone). In
1978, part 135 was substantially revised for passenger-carrying
operations over the top or in IFR conditions to require an aircraft to
be able to descend under VFR if its engine fails (43 FR 46742; October
10, 1978). This revision also provided for ``limited IFR'' operations
which, if VFR conditions were forecast within 15 minutes flying time,
allowed flight in IMC for the first 15 minutes of flight, and
thereafter only if those IFR conditions were unforecast. Under the
current regulation, a pilot can operate in IFR conditions if unforecast
weather conditions are encountered while en route on a flight planned
to be conducted under VFR. The pilot can make an IFR approach at the
destination airport if unforecast weather conditions are encountered
that do not allow an approach under VFR. This rule had the effect of
eliminating the buffer zone provisions, restricting planned flights
under IFR in IMC, and restricting VFR over-the-top flights to scattered
or broken sky conditions. An exception to the two pilot requirement, or
autopilot requirement, is provided for limited IFR operations in
Sec. 135.103. Currently, limited IFR can be conducted as a single-pilot
operation in aircraft with nine or fewer passenger seats. Cargo-only,
single-engine aircraft can operate under IFR over the top without these
restrictions.
Since 1978, the FAA has received 12 petitions for exemptions from,
or amendments to Sec. 135.181 to allow the use of all or specific
models of single-engine aircraft in passenger-carrying IFR operations.
Internationally, commercial operators in several countries have sought
permission to conduct passenger operations in IMC with single-engine
aircraft. Canada, following a cooperative effort with the engine
manufacturers, aircraft manufacturers, and users that produced a well-
documented case, has allowed SEIFR passenger-carrying operations in
turbine-powered airplanes since February 1993, with a number of
specific requirements for equipment and training. Other countries are
also considering permitting SEIFR passenger-carrying operations.
In response to the petitions, the Canadian action, and changes in
technology that have resulted in increasingly reliable engines and
aircraft systems, the FAA asked its Office of Integrated Safety
Analysis to conduct a study to determine if demonstrable differences
exist between single- and multi-engine aircraft in visual
meteorological conditions (VMC) and IMC. The study, Part 135 Single-
Engine Instrument Flight Rules Operations in instrument Meteorological
Conditions, February 24, 1994, (available in the docket) reviewed the
basis for the Canadian action and available data from a number of
sources on powerplant/systems reliability and activity exposure data.
In September 1994, the FAA asked the Aviation Rulemaking Advisory
Committee (ARAC) to review the Canadian policy on SEIFR, re-examine FAA
policies for commercial IMC and night operations by single-engine
aircraft, determine conditions or limitations that such operations
should meet, and recommend any changes. The ARAC formed a working group
that included representatives of the FAA, Transport Canada-Aviation,
the European Joint Aviation Authority (JAA), Australian Civil Aviation,
several European national aviation authorities,
[[Page 42365]]
aircraft and engine manufacturers, trade associations, pilot unions,
and commercial operators. The committee recommended that Sec. 135.181
be revised to permit SEIFR passenger-carrying operations provided
certain requirements for equipment and training were met. The ARAC
proposal, although not technically limited to a particular type of
aircraft, proposed certain conditions that are met at present only by
turbine-powered aircraft. The ARAC also recommended approval of the
Alaska Air Carrier Association's (AACA) petition for exemption, which
covers both turbine-powered and reciprocating engine aircraft. Both the
ARAC and the FAA study focused on the issue of engine reliability.
In 1995, the National Transportation Safety Board (NTSB) completed
a study of operations in Alaska, Aviation Safety in Alaska, (Safety
Study NTSB/SS-95/03, PB95-917006, November, 1995). The NTSB noted that,
unlike the rest of the U.S., commuter airline service in Alaska is
``dominated by single-engine airplanes powered by a reciprocating
engine operating under VFR and crewed by one pilot.'' After reviewing
Alaska aviation accidents from 1988 to 1993 (which include single and
multi-engine aircraft), the NTSB concluded that ``VFR flight into IMC
that result in fatal accidents continues to be the most significant
safety problem in Alaskan aviation.'' VFR flight in IMC in Alaska
accounted for 67 percent (6 of 9) fatal commuter airline accidents and
47 percent (7 of 15) of the fatal air taxi accidents. Overall, in
Alaska, VFR flight into IMC accounted for only 15 percent of the total
accidents, but 54 percent of the fatal accidents. The NTSB recommended
that the FAA proceed with rulemaking to allow SEIFR passenger-carrying
operations in turbine-powered aircraft and evaluate whether extending
the rule to all single-engine aircraft would provide a positive effect
on safety.
Prior to the Alaska aviation study, the NTSB conducted a study of
emergency medical service (EMS) helicopters because their accident rate
was twice the rate experienced by part 135 on demand helicopter
operations and one and one-half times the rate for all turbine-powered
helicopters. For the report, Safety Study--Commercial Emergency Medical
Service Helicopter Operations (NTSB 1988), the NTSB investigated and
evaluated 59 helicopter accidents in the rapidly growing commercial EMS
helicopter industry. The Board determined that marginal weather
conditions and inadvertent flight into IMC remain the most serious
hazard that VFR helicopters encounter. ``The Board believes that
although the IFR system is not designed optimally for IFR helicopters
and that the nature of the EMS helicopter mission further complicates
this problem, the safety advantages offered by IFR helicopters flown by
current and proficient pilots are great enough that EMS programs should
seriously consider obtaining this capability.''
The Alaska Air Carriers Association in its petition for exemption
has stated, and the NTSB study confirmed, that in many areas, only
single-engine aircraft can be operated because of the limitations of
the landing strips, which severely restrict the availability of air
transport in these areas. The petitioners further stated that under the
current rule, unless clear weather is forecast over the entire route
from 15 minutes from the departure airport to the destination,
passenger-carrying, single-engine commercial operations are not
permitted. In many areas, aircraft are the only means of
transportation; weather forecasts, when available, rarely predict
continuing VFR conditions. Alaska, they stated, was particularly
disadvantaged by the current rule.
The FAA reviewed accident data from 1983 to 1996 on both
reciprocating and turbine engines. Data indicated that there were 67
accidents in on-demand operations that involved VFR flight into IFR
conditions; single-engine aircraft were involved in 75 percent of these
accidents. Although the number of such accidents is known, the rate of
such accidents cannot be determined because the FAA does not collect
data on the number of flights or flight hours for on-demand operations
under part 135.
Based on its analyses, the FAA, on December 3, 1996 (61 FR 64230),
issued a notice of proposed rulemaking (NPRM) to amend part 135 to
allow passenger-carrying SEIFR operations subject to the following
conditions:
Each certificate holder should incorporate into their
manufacturer's recommended maintenance program or FAA-approved
maintenance program an engine trend monitoring program including an oil
analysis at each 100 hours interval and a record of the findings; and
Each aircraft should have two independent electrical power
generating sources or a standby battery that can maintain 150 percent
of the minimum electrical load for at least one hour to operate
navigation and communication equipment.
The FAA proposed to eliminate the limited IFR provisions, permitted
under the previous rule, for both single and multi-engine aircraft. In
addition, the FAA sought comments on the need for redundant power
sources for gyroscopic instruments. As the NPRM noted, allowing SEIFR
operations also imposed on such operations all of the existing
requirements for IFR operations, including additional equipment, an
autopilot or second pilot, increased pilot experience, and more pilot
training.
In response to the NPRM, the FAA received over 200 comments from
government entities, trade associations, pilots, air carriers,
manufacturers, and individuals. Seven comments opposed all or part of
the proposed rule. Today's final rule reflects a consideration of the
comments received, which are discussed in Section III.
II. Overview of the Final Rule
The rule promulgated today allows SEIFR operations in both turbine-
powered and reciprocating engines subject to the following conditions:
The certificate holder must incorporate into its
maintenance program either the manufacturer's recommended engine trend
monitoring program, which includes oil analysis, if appropriate, or an
FAA approved engine trend monitoring program that includes an oil
analysis at each 100 hour interval or at the manufacturer's suggested
interval, whichever is more frequent; the certificate holder must
maintain a record of the results from these trend monitoring programs
in the engine maintenance records.
Each aircraft must have two independent electrical power
generating sources each of which is able to supply all probable
combinations of continuous inflight electrical loads for required
instruments and equipment; or in addition to the primary electrical
power generating source, a standby battery or an alternate source of
electric power that is capable of supplying 150% of the electrical
loads of all required instruments and equipment necessary for safe
emergency operation of the aircraft for at least one hour.
Each aircraft must have two independent sources of energy
(with means of selecting either), of which at least one is an engine-
driven pump or generator, each of which is able to drive all gyroscopic
instruments and installed so that failure of one instrument or source
does not interfere with the energy supply to the remaining instruments
or the other energy source unless, for single-engine aircraft in all-
cargo operations only, the rate-of-turn indicator has a source of
energy separate from the bank and pitch and direction indicators.
[[Page 42366]]
Allowing SEIFR operations means that any certificate holder
conducting such operations must meet all existing requirements for IFR
operations, including those for equipment (e.g., vertical speed
indicator, free-air temperature indicator, heated pilot tube, marker
beacon receiver), crew (a second pilot or autopilot), pilot training
and testing (proficiency check every six months), and pilot experience
(1,200 hours). The new requirements will ensure that operators have an
engine trend monitoring program, as well as written maintenance
instructions. In addition, the rule requires that aircraft have
redundant systems to provide needed power to maintain critical flight
instruments as well as the necessary navigation and communications
capability.
Because the FAA is deleting the limited IFR provision, this rule
will not take effect until May 3, 1998. This will allow operators the
time to obtain the required equipment, retrofit aircraft, and revise
their operations authority and manuals. Limited IFR provisions will
remain in effect until that time. The FAA is also adopting a Special
Federal Aviation Regulation (SFAR) No. 81 that will allow operators who
can meet the requirements of the rule to begin SEIFR operations prior
to the effective date of the rule, provided an information collection
is approved and an OMB control number is assigned. Therefore, the SFAR
will not take effect until the FAA has published a notice in the
Federal Register specifying the effective date. It is anticipated that
this notice will be published within 60 days.
As explained in the NPRM, in the past, the rationale against SEIFR
passenger-carrying operations centered on the hazards of losing an
engine. Analysis indicates, however, a far more significant accident
category: Flight under VFR into IMC. As discussed above, a recent NTSB
study of aviation in Alaska indicated that VFR flight into IMC caused a
disproportionate number of fatal accidents in part 135 operations in
that state. Multi-engine airplanes are able to file and fly with
passengers under IFR, while single-engine airplanes are only able (with
few exceptions) to carry passengers under VFR. Thus, multi-engine
airplanes have the advantage of contact with ATC, position following,
en route and terminal weather information, and the higher altitude
ensuring obstacle clearance and radio reception in the IFR system.
Further, for IFR operations, part 135 requires additional fuel to be
carried, and more stringent weather reporting requirements.
The FAA Administrator, in a November 18, 1994 letter to pilots
(``Winter Operations Emphasis Program 1994,'' available in the docket),
expressed his concern about the number of accidents that occur when
pilots are flying just below a low ceiling and collide with the
terrain. He stated that one of the safest steps available was to take
advantage of the IFR system. Aircraft flying at a published cruising
altitude that guarantees obstacle clearance and radio reception have
considerably more time to glide to a landing and maneuver to a safe
landing area, whether VMC or IMC, than those flying below the ceiling.
The number of accidents involving VFR flight into IMC is
substantial. It is concern with this safety hazard that prompted the
FAA to reconsider its limitations on single-engine IFR flight with
passengers under part 135. Additionally, the FAA has considered the
action of Canada that allowed single-engine passenger-carrying IFR
under certain conditions, and the petitions for exemption of the Alaska
Air Carrier Association and individual operators. The FAA concluded
that this rule will reduce the number of accidents by allowing
operators to take advantage of the IFR system and the significant
safety benefits it provides.
The FAA is aware that other nations have either not allowed SEIFR
or have limited it to turbine-powered aircraft. In the U.S., however,
single-engine aircraft are already allowed to conduct passenger-
carrying operations under VFR in both day and night, and in IFR
conditions under the limited IFR provisions, if they meet existing
requirements for IFR operations. Also, single engine cargo operations
are presently authorized under IFR. The limited IFR rules have created
a situation where pilots who encounter IMC must either file an IFR
flight plan while en route or attempt to maintain VFR by flying below
the ceiling. The FAA determined that safety would be improved if
operators could complete adequate preflight planning and a file a
flight plan in advance, take advantage of the IFR system while en
route, and maintain the obstacle clearance provided by flying at higher
altitudes.
Paragraph 5.1.2 of Annex 6, Part 1 of the ICAO standard states,
``Single engine aeroplanes shall only be operated in conditions of
weather and light, and over such routes and diversions therefrom, that
permit a safe forced landing to be executed in the event of engine
failure.'' The ability to make such a safe landing will be enhanced if
the aircraft is in the IFR system because it will be flying at a higher
altitude, which provides more time to select a location and glide to a
landing. In addition, the aircraft would be on an established route,
with guaranteed communications, with ATC assistance readily available
to select an appropriate landing area, or advise/direct search and
rescue.
III. Discussion of Comments
The FAA received over 200 comments on the SEIFR proposed rule.
Seven of the commenters oppose the rule; all of these commenters
propose changes to the rule. The remaining commenters state their
support for the rule based on the reasons given in the NPRM for the
proposal. A number of rule supporters suggest changes to the rule, or
requested clarification of the technical requirements.
A. General Opposition
The Air Line Pilots' Association (ALPA) and Raytheon Aircraft
Corporation both oppose the rule as a whole on the grounds that VFR
flight into IMC is illegal and could be prevented by other means. They
state that the FAA's solution is inherently unsafe. The commenters
state that VFR flight into IMC could be prevented by increasing weather
minimums or imposing penalties for illegal operations. They state that
single-engine aircraft will never be as safe as multi-engine aircraft
in the same operating conditions. They further state that the rule
would increase the accident rate and that FAA data indicate the
accident rate from propulsion system failure is eight times higher for
single-engine than for multi-engine aircraft. A commenter states that
more than 18 percent of single-engine propulsion failures occur in IMC.
The FAA notes that the current VFR standards represent a level of
safety which experience has shown to be acceptable. Increasing VFR
minimums would not address the problem of VFR flight into IMC. An
increase in the current VFR minimums could, unnecessarily, restrict
part 135 operators who are limited only to VFR operations. Adequate
penalties already exist for violations of these regulations.
VFR flight into IMC is generally the result of inaccurate weather
reports or unavailable forecasts. In deteriorating conditions, pilots
are forced to fly at lower altitude to maintain VMC (or VFR
conditions). The FAA determined that this rule will improve this
situation by requiring additional fuel reserves and weather reporting
necessary for IFR operations; by providing immediate assistance by ATC
to the affected crew; by guaranteeing radio communication
[[Page 42367]]
from a minimum enroute altitude; by providing quicker notification of
search and rescue assistance, all the while having additional
assistance in the cockpit of another crewmember or autopilot.
Therefore, the FAA has determined that this amendment will create a
safer flying environment than the environment provided for in the
current rules.
The number of engines is only one factor of many that leads to a
successful flight. The FAA is improving the total operating environment
with this amendment. The single engine IFR passenger-carrying operation
will be a planned operation (IFR preflight planning of routes, weather,
fuel, and alternates), conducted in an ATC controlled environment, with
better trained and qualified pilots, with additional equipment
(autopilot if not two pilots, backup electrical and pneumatic sources),
and backed by an improved maintenance program that includes engine
health monitoring. It also is important to note that single-engine
aircraft are already permitted under the current regulations to carry
passengers during both day and night in VFR conditions, and under
limited IFR conditions. Also, single engine cargo operations are
presently authorized without having to meet the limited IFR provisions.
Thus, the FAA has already endorsed the use of single-engine aircraft in
air transportation. This amendment will make the total operating
environment for these aircraft safer for the traveling public.
B. Turbine Versus Reciprocating Engines
Although many commenters support the extension of this rule to all
single-engine aircraft, several commenters state that the rule should
be limited to turbine-powered aircraft. These commenters state that
adequate data on engine reliability exist only for turbine-powered
aircraft. Transport Canada states that the NPRM is ``almost totally
lacking in the safeguards we included in our rule to mitigate the risks
inherent in SEIFR.''
Further, Transport Canada states that it is not convinced that
opening SEIFR to all single-engine aircraft without restriction will
achieve the FAA's safety goals. Transport Canada also is not convinced
that trend monitoring for reciprocating engines can provide the same
reliable information and warnings that similar programs for turbine
engines provide. It states the belief that only turbine-powered engines
offer sufficient reliability.
The Joint Aviation Authority of Europe (JAA) states that it has no
intention of including reciprocating-powered engines in its proposal to
allow limited commercial travel and IMC flight for single-engine
aircraft. JAA's proposal will be limited to turbine-powered engines and
require a flight proficiency test, an area navigation system, autopilot
or two pilots, specific approval on the air operator certificate, a
radio altimeter, airborne weather equipment, a continuous ignition
system, a shoulder harness for passengers, and supplemental oxygen for
pressurized aircraft. In addition, terrain onto which a forced landing
can be made should be available at all phases of flight. JAA states
that ``the absence of any consideration of the ability to carry out a
forced landing in the event of an engine failure seems to the JAA not
to accord with the Standard in ICAO Annex 6, Chapter 5, Paragraph
5.1.2.''
In response, the FAA understands the concerns expressed by these
commenters, but upon consideration, has determined that this amendment
should apply to both reciprocating and turbine-powered aircraft. In
examining the types of accidents that were occurring, the FAA
determined that there would be a positive benefit to extending the rule
to all properly certificated airplanes. The amendment addresses a
number of factors, i.e., improved maintenance programs, more detailed
preflight planning, operations in the IFR system, immediate assistance
from ATC, second pilot or autopilot, and improved pilot training and
qualifications. When combined, the FAA expects these improvements to
save lives. Additionally, in their comment to the proposed rule change,
the NTSB supported the proposal stating that the ``Board accepts the
FAA's conclusion that a positive effect on safety would be obtained by
approving commercial, passenger-carrying IFR operations in single-
engine airplanes powered by both turbine and reciprocating engines,
subject to the additional equipment and operating limitations.''
SEIFR operations under part 135 are not without restrictions.
Operators who choose to use single-engine aircraft in part 135
passenger-carrying operations must comply with all the additional
equipment and training requirements that apply to IFR operations.
In response to JAA's concerns regarding harmonization, the FAA
fully supports harmonization efforts with JAA and Transport Canada,
where appropriate. JAA's proposal is concerned largely with a European
aeronautical and geographical environment. The FAA has required in this
rulemaking many of the items proposed by JAA; however, the FAA believes
that JAA's full proposal would have the effect of deterring
participation of operators of single-engine part 135 aircraft in the
IFR system and by so doing, contribute to the type of safety situation
that this rule seeks to improve.
Additionally, the FAA recognizes that Transport Canada has taken
the lead with allowing operations with single engine turbine aircraft.
In fact, the FAA considered Transport Canada's work as it developed its
proposal. The FAA will continue to support harmonization efforts to the
maximum extent practicable; however, because of its large aircraft
population operating under part 135 and its extensive IFR system, the
FAA will continue to address aviation safety issues in the United
States in light of its unique situation. The FAA notes, however, that
to the extent that Canada's aviation rules preclude the use of single-
engine aircraft powered by reciprocating engines in IFR operations,
then such U.S. certificated single-engine operations may not be able to
conduct single engine, passenger-carrying operations in Canadian
airspace.
Therefore, the FAA intends to file a difference to the single-
engine operational standard of Annex 6, Chapter 5, Paragraph 5.1.2. to
become effective upon the effective date of the SFAR.
C. Equipment Requirements
Independent Generators/Second Battery Requirement
A number of commenters state that it would be too costly for
electrical systems to provide a second battery capable of supplying 150
percent of the minimum electrical load for a least one hour, as
proposed. One commenter says that such a battery would weigh 30 pounds
and result in a more complex electrical system increasing the
probability of electrical failure. Another commenter writes that he
does not know of such a system that is widely available, reliable, and
reasonable in cost. Instead of requiring a standby battery system, the
commenter proposed requiring an ``easily noticeable warning light,''
which indicates immediately that the power generating source is
failing. Several commenters suggest a requirement to carry a handheld
transceiver, perhaps with an alkaline battery pack, to address concerns
about the loss of the airplane battery or alternator/generator. In
general, commenters who disagree with the requirement for a backup
power supply argue that there is enough redundancy currently required.
[[Page 42368]]
In response to comments, the FAA, in the final rule, requires
either two independent electrical generating sources, or a standby
battery or an alternate electrical source to serve as a second power
source (as opposed to specifying only a battery) if that source can
supply 150% of the electrical loads necessary for emergency operations
of the aircraft for at least one hour. This requirement introduces
redundancy for the generator and alternator and ensures that, if a
generator or alternator fails, the aircraft will still be able to use
certain equipment for a period of time in which to make a safe approach
and landing.
A handheld transceiver is not on the aircraft equipment list;
because such equipment is not permanently installed, its presence on an
aircraft could not be assured and, therefore, it would not meet the
regulatory requirement. In reference to the comment recommending a
warning light system, the FAA has determined that such a system
provides no redundancy and would only identify a failure as it is
happening rather than providing the aircraft with electrical power for
needed equipment for at least one more additional hour after the
failure of the primary system has occurred.
Further, the FAA believes that an alternate electrical source, such
as a standby battery, that would be approved for use in a single-engine
IFR will be a cost effective means of providing a level of safety
equivalent to an aircraft with a dual electrical system. The FAA has
used the phrase ``alternate source of electric power'' in this
amendment. Although the FAA envisions that alternate source to be a
battery or an electrical storage unit, the wording provides for future
technology that may replace a simple battery.
The NPRM proposed, as an alternative to having two independent
electrical generating sources installed on the aircraft, a single
generating source and a standby battery capable of supplying 150% of
the minimum electrical load for at least one hour to operate navigation
and communication equipment. Commenters raised questions as to what was
meant by the term ``minimum electrical load'' as it pertains to the
capacity of the standby battery. Upon further review, the Agency
recognizes that the proposed Sec. 135.163(f)(2) regulatory language did
not comport with its intent regarding the electrical loads that the
standby battery must be capable of providing.
Therefore, in this final rule, the Agency is clarifying its intent
that the standby battery be capable of supplying 150% of the electrical
loads for all required instruments and equipment necessary for the safe
emergency operation of the aircraft for one hour. This is consistent
with the redundancy requirements specified for multiengine aircraft in
Sec. 135.163(g). The FAA further recognizes that in an actual emergency
situation, the pilot will shed electrical loads to the minimum required
for safe operation. Required instruments and equipment could include
single navigation and communication equipment, but could also include
other equipment necessary for the safe operation of the aircraft in the
actual environment, such as pilot heat or instrument lighting. The FAA
is therefore deleting both the phrase ``minimum'' and ``to operate
navigation and communication equipment'' from the regulatory language
to clarify that the battery capacity is not limited solely to the
capacity needed to operate navigation and communication equipment, but
other necessary equipment as well. Thus, should an operator choose not
to install two independent electrical power generating sources on the
aircraft, this alternate minimum electrical power source will provide
the necessary system redundancy for safe emergency operation of the
flight.
The FAA further finds that although it did not propose this precise
language in the NPRM, it is unnecessary and not in the public interest
to delay the entire single-engine IFR rulemaking on this minor
technical issue. Nevertheless, the FAA invites comment on the final
regulatory language in Sec. 135.163(f)(2).
Redundant Power Source for Gyroscopic Instruments
The FAA specifically sought comments on whether a redundant power
source for gyroscopic instruments is needed. One commenter responds
that requiring dual engine-driven, pneumatic pumps would go a long way
to precluding loss of air-driven gryos. If both pumps were lost because
the engine stopped, the battery should last long enough to allow the
aircraft to glide to a landing. One commenter states that French IFR
rules achieve redundant gyroscopic instruments with one attitude
indicator and a second attitude indicator or a turn indicator and a
slip indicator powered by a source independent of the first attitude
power source. Another commenter states that a third attitude indicator
should be installed with at least 3-minute self-contained electrical
source independent of the aircraft's main electrical system. The NTSB
recommended a requirement for a redundant source of power for attitude
gyroscopic instrumentation. The Board stated that despite requirements
for partial panel training, the fatal accident record indicates that
many pilots have experienced difficulty maintaining aircraft control
during actual partial panel situations. Another commenter, however,
states that because there are so few system failures in IFR flight,
redundant systems for gyroscopes are unnecessary.
By this amendment, the FAA has adopted the proposed requirement for
redundant power sources for gyroscopic instruments to the final rule.
Although the NPRM did not contain the regulatory language, the Agency
proposed the redundant power source requirement in the preamble. The
FAA recognized that the failure of the vacuum/pressure pump of the
pneumatic system during IFR in IMC can lead to spatial disorientation
of the pilot and loss of aircraft control. The redundancy or the
pneumatic system will put single-engine aircraft systems on parity with
existing twin-engine aircraft. Because the FAA proposed redundancy for
passenger-carrying operations, but not for all-cargo operations, the
final rule requirement for redundancy of power source for gyroscopic
instruments is limited to passenger-carrying operations.
Autopilot/Co-pilot Requirement
Several commenters state that the proposed rule does not
substantiate the need for two pilots or a single pilot with autopilot.
There are concerns because the vast majority of single engine aircraft
do not have an autopilot installed that meets the requirements of
Sec. 135.105, and retrofitting such aircraft may cost up to $20,000 and
add up to 30 pounds to the empty weight of an aircraft. In addition,
according to the commenter, if another crewmember is added to comply
with the regulation, one less seat would be available on the small
planes, which would be a ``severe economic burden.'' Another commenter
states that the FAA should allow two-axis autopilots; a requirement for
a three-axis autopilot would eliminate most single-engine aircraft
currently equipped with autopilots.
In response, the FAA disagrees that an autopilot or second pilot is
not needed. The complexity and workload in IMC is such that a three-
axis autopilot as opposed to a two-axis autopilot, or second pilot is
necessary for safety in air transportation. Section 135.105 currently
establishes a standard for an autopilot capable of operating the
aircraft controls about three axes.
Concerning the comment on weight penalty and the cost issue, the
FAA has determined that these requirements, as well as the other
requirements for
[[Page 42369]]
equipment, training and checking, operations, maintenance, etc., are
based on experience and are considered necessary for safety. The FAA
has determined that they remain valid for any air carrier involved in
commercial passenger-carrying operations. Therefore, the FAA is
adopting the autopilot or second pilot as proposed.
Other Equipment
Commenters suggest other equipment that should be required for
SEIFR operations. One commenter states that a radar altimeter should be
required because it shows actual height above the terrain. Another
commenter states that for planes with six or more passengers, the FAA
should mandate an emergency cockpit checklist, a cockpit voice
recorder, and weather radar. For turbine-powered airplanes, TCAS and
GPWS should be required when carrying six or more passengers. Area
navigation systems provide an additional margin of safety where radar
coverage is minimal. A third commenter states that the NPRM does not
adequately address pitot system anti-icing. Any flight where flight
temperatures will be below 40 deg. F should require dual heated pitot
systems to ensure that the pilot will have airspeed and static system
operation in IMC. Fuel tank vents and stall warning systems need to be
ice protected. Windshield de-ice is needed for winter operations in
Alaska. The commenter also suggests self-powered attitude indicators
should be added to single-engine aircraft used for SEIFR operations.
To respond, the FAA notes that radar altimeters are only required
for Category II and III operations. As for the emergency cockpit
checklist, a cockpit voice recorder, weather radar, TCAS, GPWS, and
area navigation systems, the FAA has decided that this equipment is not
necessary for the planned operations affected by this rule.
Regarding the comment on icing, flight into icing conditions is
already prohibited by Sec. 135.227 unless the aircraft is adequately
equipped. This rule does not change the equipment requirements for
flight into icing conditions. Also, this rule does not relieve an
operator from having an aircraft certified for flight into icing
conditions, if those operations are anticipated.
D. Oil Analysis/Maintenance/Trend Monitoring/Engine Health
Several commenters are concerned about the oil analysis
requirements. Several letters mention that while oil analysis as part
of a maintenance program may be justified, expensive engine maintenance
should not be required based solely on this one parameter. According to
the commenter, one ``bad'' sample is not sufficient reason for
maintenance until further analysis is performed. Oil samples may be
misleading because it is possible to have sample contamination; as the
commenter noted, a single operation on a dusty day with the carburetor
heat left on accidentally allowing unfiltered air into the engine may
create a contaminated sample. The commenter suggests that other tools,
such as compression checks and borescopes, should be used in
conjunction with oil analyses.
Another commenter states that oil analysis has never enabled him to
predict, and therefore avoid, engine problems. He gave an example of
one instance where a turbocharger broke down, filling the engine's oil
screen with metal. After contacting the oil lab to find out why the oil
analysis tests had not predicted the failure, the lab indicated to him
that the particles of metal in the oil were ``too big'' to be detected
by regular analysis.
One commenter says that those in the oil analysis business are
concerned about their liability insurance if their opinion is mandated
rather than advisory. Another commenter writes that oil analysis should
not be required at each 100 hours of inspection, but rather at 100
hours of operations because not all oil changes are made at 100-hour
inspections. Other commenters suggest replacing ``oil analysis'' with
``trend monitoring and/or oil analysis.'' Finally, two commenters
suggest requiring ``oil analysis'' and an oil and filter change every
50 hours rather than 100 hours. Another commenter states that
spectrographic oil analysis is not a predictor of fatigue failures,
which are the most common cause of piston-engine power loss.
FAA has determined that engine health trend monitoring can play an
important part in preventive maintenance by providing an early warning
of potential problems. The final rule gives operators the option of
adopting the manufacturer's trend monitoring program or an FAA-approved
trend monitoring program that includes oil analysis. The FAA is
currently updating its advisory materials on trend monitoring programs
(AC 21-105A, ``Engine Power Loss Accident Prevention,'' dated 11/20/
80).
While the FAA recognizes that the possibility exists for misleading
oil analyses, each laboratory analysis report must be treated
individually and in conjunction with previous reports. If the data
indicate a possible problem exists, further inspection and/or
maintenance is necessitated. This approach is consistent with the
current practice of inspection if one of the engine's cylinders had a
bad compression reading because carbon deposits were keeping a valve
from properly seating.
FAA has determined that a spectrographic oil analysis, properly
performed, provides the owner/operator with a reliable, advance warning
of a potential failure based on the amount of metal and bearing
material in the oil sample. Although contamination can occur at any
stage, in a comprehensive maintenance inspection program, oil analysis
will provide useful trend information. The FAA agrees with the comment
that oil analysis will not always give advance warning of fatigue
failures, such as crankshaft separation, but neither do other
inspection techniques, such as borescope inspections and compression
tests.
Regarding the recommendation to change the interval of oil sampling
from 100 hours to 50 hours, the FAA notes that 100-hour interval is
considered an ``industry standard.'' Under the final rule, operators
must follow the manufacturer's monitoring program recommendations if
they call for more frequent checks.
The FAA also recognizes that oil analysis may not be applicable to
certain engine types, e.g. Pratt and Whitney PT-6. Therefore, in the
final rule, the operator is given the option to choose between the
manufacturer's published trend monitoring program, which may or may not
contain a provision for oil analysis based on the engine type and
design, or the FAA-approved program that must include oil analysis.
Published manufacturer's trend monitoring programs are available for
turbine engines, however, the FAA is not aware of any published trend
monitoring program for reciprocating aircraft.
To clarify the recordkeeping requirements, the FAA has added a new
Sec. 135.421(e) to require the recordation and maintenance of the
results of each test, observation, or inspection required by the
applicable engine monitoring program in the engine maintenance records.
Although the FAA proposed a recordkeeping requirement for the engine
trend monitoring, the FAA requests comment on the modification to the
recordkeepng requirement to be codified in Sec. 135.421(e). The
required recordation is subject to OMB approval, as required by the
Paperwork Reduction Act. An information collection control number will
be assigned for it if and when OMB approval is given; that
[[Page 42370]]
number would be listed in part 11, subpart F, of Title 14.
E. Training
One commenter suggests that training should emphasize partial panel
operations and systems failure recognition; such training could be
included in part 135 training manuals. Another commenter states that an
ATP certificate should be required for SEIFR operations. Commenters
also suggest that simulator training and a six-month IFR check should
be required.
The FAA agrees with the commenter that additional emphasis and
checking in partial panel and system failure recognition are necessary.
Existing regulations require training in systems failures. The FAA will
review and update its handbooks and training related material to ensure
that partial panel operations are evaluated on the instrument
competency checks for the affected operators and that proper attention
is given when operators' training programs are approved and reviewed.
In addition, the FAA notes that an ATP certificate is required for
pilot-in-command positions on large airplanes usually operated under
part 121. The experience and skill level required for single-engine air
transportation under IFR are not equivalent to those required for large
transport category airplanes. The FAA maintains that a commercial pilot
certificate and appropriate ratings are sufficient qualification for
operations conducted under this rule; part 135 requires 1,200 hours of
flight time for IFR operations. On simulator training, the FAA notes
that part 121 does not require simulator training. Simulators are not
available for most of the types of aircraft that will operate under
this rule. For those aircraft that have simulators available, operators
are encouraged to use them. Also, some training may be accomplished in
a training device (Sec. 135.347). The FAA does not believe that
required simulator training is necessary for adequate safety for the
anticipated operations. Last, a six-month instrument proficiency check
is already required (Sec. 135.297) by the existing regulations.
F. Removal of Limited IFR
Several commenters believe that the elimination of the present
``limited IFR'' rules would not be in the best interest of safety. They
believe that operations in limited IFR conditions allowed by
Secs. 135.103 and 135.181 should still apply to single-engine airplanes
without autopilots because the rules allow a qualified pilot to make an
approach if, due to unforecast weather, the intended destination goes
below VFR minimums. Another commenter does not favor eliminating these
sections because pilots would lose the ability to climb out of the low
level fog layer that often persists at some airports during the morning
hours of the day. One commenter argues for maintaining the ``limited
IFR'' rule because it is safer to offer the ability to operate under
limited IFR rather than to force a pilot to scud run in and out of an
uncontrolled field, or face delays at a tower controlled field, all the
while watching the weather conditions worsen. Another commenter
suggested amending Sec. 135.103 to exempt the autopilot for this
section.
Current data, as discussed in the NPRM, for on-demand Part 135
accidents involving single-engine aircraft indicate that poor inflight
planning and decision-making, and other weather-related errors
resulting from attempts to maintain VFR flight are the major causes of
accidents. While the possibility of a failure of the single engine
exists, the FAA has, it believes, reduced that possibility further by
additional maintenance requirements. The possibility of pilot
mishandling has also been reduced, in the judgment of the FAA, by
emphasizing training in partial panel emergency procedures and system
failure recognition when combined with equipment redundancies.
As mentioned above, the FAA is improving the total operating
environment with this amendment. A single-engine passenger-carrying
operation will be a planned operation (IFR preflight planning of
routes, weather, fuel, and alternates), conducted in an ATC controlled
environment, with better trained pilots, with additional equipment
(autopilot if not two pilots, redundant electrical and vacuum systems),
backed by an improved inspection program that includes engine trend
monitoring. Therefore, the FAA has not retained the limited IFR rule
because the FAA concluded, based on available data, that planned flight
under IFR provides a higher standard of safety than unplanned flight
under the limited IFR rule.
G. Weather and Terrain Issues
Transport Canada states that flight under IFR requires that the
aircraft be certified for flight into known icing for at least the
northern U.S.; few existing single-engine aircraft in commercial
service are so certified. Another commenter states that icing is a
greater problem than VFR flight into IMC. The greater number of
accidents due to inadvertent encounters with icing will more than
offset any improvements in the VFR to IMC accident rate. Reciprocating
engine aircraft certification rules do not require a demonstration of
any ability to continue to operate in icing conditions. In addition, a
few commenters state the SEIFR over mountainous terrain should be
barred.
The FAA recognizes that authorizing an aircraft to operate in IFR
conditions neither converts an aircraft to ``all-weather,'' nor allows
it to do anything for which it is not certificated or equipped. Under
Sec. 135.227, operators using aircraft not certified for known icing
conditions may not operate in those conditions. An aircraft that does
not meet the requirements for flying in icing conditions may not be
operated in those conditions. Additionally, the FAA notes that part 135
operators can already operate under IFR in U.S. airspace using aircraft
that are not certified for known icing as long as the operations
anticipated are outside of known icing conditions.
Single-engine aircraft limited by service ceiling or lack of
pressurization or oxygen will not be capable of using the IFR system
over some mountainous terrain. In addition, the FAA notes that finding
a suitable landing place in mountainous terrain, if a forced landing is
necessary, may not be very much different from finding a suitable
landing place in a wide, densely populated area. Single engine aircraft
are not presently restricted from either area. Thus, single engine
operations addressed in this amendment will not be so restricted
either.
H. National Application of the Rule
A commenter suggests that the FAA should limit all SEIFR operations
to only Alaska (turbine or reciprocating engine) or, at least, limit
SEIFR with reciprocating-engine aircraft to only Alaska. A commenter
states that if specific operations in remote areas require exemptions,
these should be handled on a case-by-case basis, not by adopting a
national standard. Several commenters state that this rule will result
in operators trading in multi-engine aircraft and replacing them with
reciprocating engine, single-engine aircraft.
The FAA considered the conditions of weather and terrain in Alaska
to be a ``worst-case'' operating environment. Authorization in the
regulations for use of single-engine air transportation under IFR in
Alaska would justify single-engine air transportation under IFR in the
contiguous U.S. where operating conditions are generally less severe.
The FAA's regulatory evaluation indicates
[[Page 42371]]
that this rule will create a net safety benefit in the other 49 states
as well as Alaska. Exemptions are handled on a case-by-case basis;
however, the rationale that the FAA would use to justify an exemption
would also apply to all similarly-situated operators.
The FAA does not expect the operators currently flying multi-engine
aircraft will switch to single-engine aircraft simply because of this
rule change. Decisions about the type of aircraft to operate are
complex. Operators must weigh numerous factors when selecting aircraft,
for example, aircraft availability and age, customer base, and
geographical location. Whatever choice operators make, the FAA remains
convinced that the rule will increase safety of single-engine,
passenger-carrying operations.
I. Other Comments
Several comments support the ARAC proposals. One commenter states
that the FAA received only 12 petitions for exemptions since 1978,
which is not a significant number. Finally, one commenter states the
proposal would result in slower, single-engine aircraft at metropolitan
airports, taxing the ATC system, and in more inexperienced pilots
flying in hazardous conditions. To overcome these problems, they
suggest that any aircraft that cannot maintain 140 knots on final
approach should be excluded from Class B airspace and that pilot
qualifications should include 2,000 hours of flight time.
The FAA commends the ARAC for its detailed work on the SEIFR
proposal; as is evident, the ARAC proposal formed a basis for this
action. In fact, the FAA notes that this final rule incorporates a
number of the ARAC proposals. Other ARAC proposals are not needed
because they duplicate existing requirements. The ARAC proposals,
although not technically limited to a particular type of aircraft,
cited conditions that are met at present by only turbine-powered
aircraft. The ARAC also recommended that the FAA grant the Alaska Air
Carriers Association's petition for exemption, which covers all single-
engine aircraft.
FAA rulemaking is not contingent only upon public petition. In the
case of this rule, the petitions for exemption, one of which was
submitted by a trade association, were only part of an overall, growing
awareness by industry and FAA that the limited IFR rule was no longer
serving its original purpose and that the better safety alternative
would be to allow all qualified part 135 operators to use the IFR
system from departure to termination of the flight.
Finally, the FAA is unaware of any evidence that this rule would
place an excessive burden on the ATC system or result in delays in the
terminal area.
IV. Maintenance of Required Equipment
Section 135.411 requires an operator of an aircraft type
certificated for 9 or fewer passengers to have that aircraft
maintained, at a minimum, in accordance with parts 91 and 43 of Title
14. The maintenance is performed on the basis of 100-hour and annual
inspections, as those inspections are described in part 43, appendix D.
For an aircraft type certificated for 9 or fewer passengers,
Sec. 135.411 also accepts an approved aircraft inspection program
(AAIP), as described in Sec. 135.419.
Section Sec. 135.419(a) provides that, when the FAA finds that the
aircraft inspections required under part 91 are not adequate to meet
part 135, the FAA may amend the operator's operations specifications to
require an AAIP. Section Sec. 135.419(f) provides that, when the FAA
finds that revisions to an AAIP are necessary for the continued
adequacy of the program, the operator must, after notification from the
FAA, make the necessary revisions. Long-standing rules, therefore,
enable the FAA to make even major adjustments to an operator's
maintenance program that are necessary to maintain the level of safety
appropriate for carrying passengers or cargo for compensation or hire.
Section 135.421(a) describes additional maintenance requirements
for each operator of an aircraft type certificated for 9 or fewer
passengers; it requires the operator to comply with the manufacturer's
recommended maintenance program, or with an AAIP, for each aircraft,
engine, propeller, rotor, and item of emergency equipment. In Notice
96-14, the FAA proposed to add paragraph (c) to Sec. 135.421 to require
the single engine aircraft operator to incorporate into its
manufacturer's recommended maintenance program or AAIP, an engine trend
monitoring program that includes a 100-hour oil analysis and record of
findings.
The equipment required under Sec. 135.105 and new Sec. 135.163 (f)
and (h) will frequently be installed in accordance with a supplemental
type certificate (STC); the holder of that certificate may be required
by 14 CFR Sec. 21.50 to furnish instructions for continued
airworthiness (ICAW), in which case, it is important that the operator
maintain the equipment in accordance with those instructions to
maintain the level of safety appropriate for carrying passengers for
compensation or hire. It is imperative for each part 135 operator, no
matter what the method of approval of the installation, to have the
equipment required by this rule maintained to the level of safety
appropriate for carrying passengers for compensation or hire.
Accordingly, the FAA has decided to adopt new Sec. 135.421(d). New
Sec. 135.421(d) will require the operator to ensure that the equipment
required by Sec. 135.105 and new Sec. 135.163 (f) and (h) is maintained
in accordance with written maintenance instructions that will provide a
level of safety equivalent to ICAW. If the manufacturer provides ICAW,
the operator may use those; to deviate from the ICAW, the operator will
be required to obtain FAA approval. New Sec. 135.421(d) applies to
operators who have 100-hour and annual inspection based programs, and
operators who have AAIPs. Therefore, if operator does not utilize the
applicable manufacturer's maintenance manual or instructions for
continued airworthiness prepared by the manufacturer, then it must have
written maintenance instructions, acceptable to the Administrator,
containing the methods, techniques, and practices to maintain the
equipment required in Secs. 135.105 and 135.163 (f) and (h).
Although this modification to the maintenance requirements was not
explicitly stated in Notice 96-14, the FAA has decided to adopt it in
this final rule. As explained above, long-standing rules enable the FAA
to make necessary adjustments to an operator's maintenance program.
Furthermore, operators should realistically expect to be required to
properly maintain all equipment that is critical to SEIFR operations.
The FAA has determined that many operators already have the items of
equipment installed in their aircraft, and are maintaining those items
in accordance with instructions that are not stated in the amount of
detail necessary for the level of safety expected for SEIFR operations.
New Sec. 135.421(d) will require those instructions to be written and
acceptable to the Administrator.
Because the FAA did not explicitly propose Sec. 135.421(d), the FAA
invites comment on that section's final regulatory language. The
required written maintenance instructions are subject to OMB approval,
as required by the Paperwork Reduction Act. An information collection
control number will be assigned for them if and when OMB approval is
given; that number would be listed in part 11, subpart F, of Title 14.
Section 135.411 requires an operator of an aircraft type
certificated for 10 or
[[Page 42372]]
more passengers to have that aircraft maintained in accordance with a
program that meets the requirements of Secs. 135.415, 135.417, and
135.423 through 135.443. That program is referred to as a continuous
airworthiness maintenance and inspection program (CAMP). Section
135.425(c) requires that a CAMP ensure that each aircraft released to
service has been properly maintained for operation under part 135.
Section 135.427(b) requires the CAMP to include the programs required
by Sec. 135.425 that must be followed in performing maintenance,
preventive maintenance, and alteration of the operator's aircraft,
including the airframe, engines, propellers, rotors, appliances,
emergency equipment, and parts. Instructions for maintaining the
equipment required by Secs. 135.105 and 135.163 (f) and (h) will be
incorporated into operators' CAMPs.
V. Section-by-Section Discussion of Changes
Special Federal Aviation Regulation (SFAR) No. 81 is added to allow
operators who can meet the requirements of this rule before the
effective date to begin SEIFR operations. The SFAR is not effective
until the FAA publishes a notice specifying the effective date in the
Federal Register. The SFAR terminates on the effective date of the
Commercial Passenger-Carrying Operations in Single-Engine Aircraft
Under Instrument Flight Rules rule.
As proposed, Sec. 135.101 is revised to eliminate the reference to
Sec. 135.103, which is deleted, and to delete the word ``conditions''
after IFR. Deletion of the word ``conditions'' clarifies that any
operation for which an IFR flight plan is filed must have a second
pilot or an autopilot, even if the flight can be conducted in VFR
conditions.
As proposed, Sec. 135.103 is deleted because it is no longer
needed.
Section 135.163 is revised to add, for multi-engine aircraft,
reference to alternators. For single-engine aircraft, a requirement is
added for two independent electrical power generating sources or a
standby battery or alternate source of electric power. A requirement is
also added for a redundant energy system for gyroscopic instruments;
the existing exception in paragraph (h) for single-engine aircraft is
not limited to single-engine aircraft in all-cargo operations.
As proposed, Sec. 135.181 is revised by dropping all of the limited
IFR conditions. Only the performance requirements for multi-engine
aircraft and over-the-top requirements remain.
Section 135.411 is revised to add a reference to Sec. 135.421 as it
pertains to the maintenance requirements for single engine passenger-
carrying aircraft under IFR.
Section 135.421 is revised to add the requirement for engine trend
monitoring for aircraft used in passenger-carrying SEIFR operations,
and the requirement for written maintenance instructions, acceptable to
the Administrator, for the equipment required in Secs. 135.105, and
135.163 (f) and (h).
Regulatory Evaluation Summary
The Federal Aviation Administration (FAA) is updating and revising
the regulations to allow single-engine, passenger carrying aircraft to
operate under the instrument flight rules. The rule will reduce the
incentive for operators to conduct low altitude operations under
marginal weather conditions. However, this rule will also require
operators to meet the more stringent requirements for such flights
including additional aircraft equipment.
The cost of this final rule is estimated at $170.3 million ($127.6
million, discounted). The most costly provision is on the requirement
for an autopilot, which is estimated at $94.9 million discounted and
represents about 74.3 percent of the total. The FAA concludes that the
expected quantitative benefits will be $354.6 million or $249.1
million, discounted. If the rule is 75 percent effective in reducing
fatalities and injuries, then the expected quantitative benefits will
be $284.3 million or $199.5 million discounted over ten years. The
benefits estimate should be considered low because the added equipment,
etc. required for single-engine aircraft should result in fewer overall
fatalities. The benefits analysis does not take this into account.
If fewer disruptions, cancellations, etc. were considered a cost-
savings instead of a benefit, then both the benefit estimate and the
cost estimate should be reduced by $156.9 million ($110.2 million
discounted). The cost of the rule, net of these costs savings, will be
$13.4 million or $17.4 million, discounted, and the benefits of this
rule, namely safety benefits (assuming 75 percent effectiveness), will
be $127.7 million or $89.3 million discounted over ten years. While the
discounted costs and benefits are lower than the undiscounted costs and
benefits, respectively, the discounted net costs are higher than the
undiscounted net costs.
Under the guidelines presented in FAA Order 2100.14A, the FAA has
determined that the final rule will not have a significant economic
impact, positive or negative, on small operators.
This final rule is not expected to have any impact on trade
opportunities for U.S. firms doing business overseas or foreign firms
doing business in the United States. The final rule will primarily
affect U.S. operators of aircraft for hire that provide domestic
service.
This final rule does not contain any Federal intergovernmental or
private sector mandate. Therefore, the requirements of Title II of the
Unfunded Mandates Reform Act of 1995 do not apply.
Regulatory Flexibility Assessment
The Regulatory Flexibility Act of 1980 (RFA) was enacted by
Congress to ensure that small entities are not unnecessarily or
disproportionately burdened by Federal Regulations. The RFA requires an
analysis if a final rule will have ``a significant economic impact on a
substantial number of small entities.'' The definitions 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 outlines
the agency's procedures and criteria for implementing the RFA.
With respect to the final rule, a ``small entity'' is an operator
of aircraft for hire with nine or fewer aircraft. A ``significant
economic impact on a small entity'' is defined as an annualized net
compliance cost for operators of aircraft for hire which in 1996
dollars is $126,100 for scheduled operators whose aircraft have more
than 60 seats. It is $70,490 for scheduled operators whose fleets have
aircraft with seating capacities of 60 or fewer seats (other scheduled
operators) and $4,960 for unscheduled operators. A substantial number
of small entities is defined as a number that is 11 or more and which
is more than one-third of small operators subject to the final rule.
The FAA estimates that the annualized cost of the final rule is
about $4,708 per aircraft and that the annualized cost savings to the
operator is about $2,142 per aircraft. Therefore, the net annualized
cost is about $2,566 per aircraft.
The FAA has initially determined that if every operator were
defined as unscheduled, then operators with two aircraft or more will
incur a significant impact.
The cost for an operator with two aircraft is slightly over the
threshold of $4,960 by approximately three and a half percent. However,
in the regulatory evaluation and the above regulatory
[[Page 42373]]
flexibility analysis, the FAA has made conservative assumptions that
could result in costs per aircraft being overestimated. For example,
the FAA has assumed that none of the aircraft are in partial compliance
with any of the equipment requirements of this regulation. To the
extent that some operators have aircraft that are in partial
compliance, then costs per aircraft have been overestimated and the FAA
believes that compliance costs per aircraft are overestimated by more
than five percent. An example of this are the weight penalty costs. The
FAA assumed that a battery and related hardware would add 30 pounds to
the weight of the aircraft. A Gill 25 amp battery weighing 22 pounds
plus hardware would be adequate and weighs about 25 pounds. Therefore,
the difference in weight (5 pounds x 15 gallons/pound x $2.32/
gallon=$174) would result in aircraft being under the threshold.
Consequently, operators with two or fewer aircraft would not likely to
be significantly impacted. The FAA has concluded that this is the case
and, therefore, the rule will not affect a substantial number of small
entities. In addition, many operators that the FAA considered as being
potentially impacted may choose not to carry passengers under IFR. For
these reasons, the FAA has determined that a substantial number of
operators will not be positively or negatively impacted in a
significant way.
International Trade Impact Statement
This final rule is not expected to have any impact on trade
opportunities for U.S. firms doing business overseas or foreign firms
doing business in the United States. The final rule will primarily
affect U.S. operators of aircraft for hire that provide domestic
service.
Unfunded Mandates Reform Act Assessment
Title II of the Unfunded Mandates Reform Act of 1995 (the Act),
enacted as Pub. L. 104-4 on March 22, 1995, requires each Federal
agency, to the extent permitted by law, to prepare a written assessment
of the effects of any Federal mandate in a proposed or final agency
rule that may result in the expenditure by State, local, and tribal
governments, in the aggregate, or by the private sector, of $100
million or more (adjusted annually for inflation) in any one year.
Section 204(a) of the Act, 2 U.S.C. 1534(a), requires the Federal
agency to develop an effective process to permit timely input by
elected officers (or their designees) of State, local, and tribal
governments on a proposed ``significant intergovernmental mandate.'' A
``significant intergovernmental mandate'' under the Act is any
provision in a Federal agency regulation that will impose an
enforceable duty upon State, local, and tribal governments, in the
aggregate, of $100 million (adjusted annually for inflation) in any one
year. Section 203 of the Act, 2 U.S.C. 1533, which supplements section
204(a), provides that before establishing any regulatory requirements
that might significantly or uniquely affect small governments, the
agency shall have developed a plan that, among other things, provides
for notice to potentially affected small governments, if any, and for a
meaningful and timely opportunity to provide input in the development
of regulatory proposals.
This final rule does not meet the cost thresholds described above.
Furthermore, this final rule will not impose a significant cost on
small governments and will not uniquely affect those small governments.
Therefore, the requirements of Title II of the Unfunded Mandates Reform
Act of 1995 do not apply.
Paperwork Reduction Act of 1995
The proposed recordkeeping requirements for the engine trend
monitoring (new Sec. 135.421(e)) and the written maintenance
instructions (new Sec. 135.421(d)) are subject to OMB approval, as
required by the Paperwork Reduction Act. Pending OMB clearance on the
paperwork requirements, SFAR No. 81 is not effective until the FAA
publishes in the Federal Register a notice specifying the effective
date. An information collection control number will be assigned if and
when OMB approval is given; that number would be listed in part 11,
subpart F of Title 14.
Conclusion
For the reasons discussed in the Preamble, and based on the
findings in the Regulatory Flexibility Assessment and the International
Trade Impact Analysis, the FAA has determined that this rule is not a
``significant regulatory action'' under Executive Order 12866. In
addition, the FAA certifies that this regulation does not have a
significant economic impact, positive or negative, on a substantial
number of small entities under the criteria of the Regulatory
Flexibility Act of 1980. This amendment is not considered significant
under Order DOT 2100.5, Policies and Procedures for Simplification,
Analysis, and Review of Regulations. A regulatory evaluation of the
regulation is available in the docket.
List of Subjects in 14 CFR Part 135
Air carriers, Air taxis, Air transportation, Aircraft, Airmen,
Airworthiness, Aviation safety, On-demand operations, Pilots,
Rotorcraft, Safety, Single-engine aircraft, Single-engine airplane.
For the reasons set out in the preamble, 14 CFR part 135 is amended
as set forth below:
PART 135--OPERATING REQUIREMENTS: COMMUTER AND ON-DEMAND OPERATIONS
1. The authority citation for part 135 continues to read as
follows:
Authority: 49 U.S.C. 106(g), 40113, 44701-44702, 44705, 44709,
44711-44713, 44715-44717, 44722.
2. Special Federal Aviation Regulation No. 81 is added to read as
follows:
SFAR No. 81--PASSENGER-CARRYING SINGLE-ENGINE IFR OPERATIONS.
1. Purpose and Eligibility.
(a) This Special Federal Aviation Regulation provides for the
approval of single-engine passenger-carrying operations under
instrument flight rules (IFR) during the month prior to the
effective date of the Commercial Passenger-Carrying Operations in
Single-Engine Aircraft Under Instrument Flight Rules rule.
(b) This SFAR terminates on May 3, 1998.
(c) Only those single-engine, passenger-carrying operations
meeting all the applicable requirements of part 135 and those
requirements set forth in paragraph 2 of this SFAR may operate under
IFR.
2. Contrary provisions of Secs. 135.103 and 135.181
notwithstanding, a person may conduct passenger-carrying operations
under IFR in single-engine aircraft if the following conditions are
met:
(a) The aircraft has two independent electrical power generating
sources each of which is able to supply all probable combinations of
continuous inflight electrical loads for required instruments and
equipment; or in addition to the primary electrical power generating
source, a standby battery or an alternate source of electric power
that is capable of supplying 150% of the electrical loads of all
required instruments and equipment necessary for safe emergency
operation of the aircraft for at least one hour;
(b) The aircraft has two independent sources of energy (with
means of selecting either), of which at least one is an engine-
driven pump or generator, each of which is able to drive all
gyroscopic instruments and installed so that failure of one
instrument or source does not interfere with the energy supply to
the remaining instruments or the other energy source;
(c) The aircraft meets the autopilot requirements of
Sec. 135.105 or has a second in command;
(d) The certificate holder's maintenance inspection program
incorporates either the manufacturer's recommended engine trend
[[Page 42374]]
monitoring program, which includes an oil analysis, if appropriate,
or an FAA approved engine trend monitoring program that includes an
oil analysis at each 100 hour interval or at the manufacturer's
suggested interval, whichever is more frequent.
(e) The results of each test, observation, and inspection
required by the applicable engine trend monitoring program are
recorded and maintained in the engine maintenance records; and
(f) Written maintenance instructions containing the methods,
techniques, and practices necessary to maintain the equipment
specified in paragraph 2 (a), (b), and (c) are prepared.
3. Section 135.101 is revised to read as follows:
Sec. 135.101 Second in command required under IFR.
Except as provided in Sec. 135.105, no person may operate an
aircraft carrying passengers under IFR unless there is a second in
command in the aircraft.
Sec. 135.103 [Removed and reserved]
4. Section 135.103 is removed and reserved.
5. Section 135.163 is amended by revising paragraphs (f), (g), and
(h) to read as follows:
Sec. 135.163 Equipment requirements: Aircraft carrying passengers
under IFR.
* * * * *
(f) For a single-engine aircraft:
(1) Two independent electrical power generating sources each of
which is able to supply all probable combinations of continuous
inflight electrical loads for required instruments and equipment; or
(2) In addition to the primary electrical power generating source,
a standby battery or an alternate source of electric power that is
capable of supplying 150% of the electrical loads of all required
instruments and equipment necessary for safe emergency operation of the
aircraft for at least one hour;
(g) For multi-engine aircraft, at least two generators or
alternators each of which is on a separate engine, of which any
combination of one-half of the total number are rated sufficiently to
supply the electrical loads of all required instruments and equipment
necessary for safe emergency operation of the aircraft except that for
multi-engine helicopters, the two required generators may be mounted on
the main rotor drive train; and
(h) Two independent sources of energy (with means of selecting
either), of which at least one is an engine-driven pump or generator,
each of which is able to drive all gyroscopic instruments and installed
so that failure of one instrument or source does not interfere with the
energy supply to the remaining instruments or the other energy source
unless, for single-engine aircraft in all-cargo operations only, the
rate-of-turn indicator has a source of energy separate from the bank
and pitch and direction indicators. For the purpose of this paragraph,
for multi-engine aircraft, each engine-driven source of energy must be
on a different engine.
* * * * *
6. Section 135.181 is amended by revising paragraphs (a)(1) and (c)
to read as follows:
Sec. 135.181 Performance requirements: Aircraft operated over-the-top
or in IFR conditions.
(a) * * *
(1) Operate a single-engine aircraft carrying passengers over-the-
top; or
* * * * *
(c) Without regard to paragraph (a) of this section, if the latest
weather reports or forecasts, or any combination of them, indicate that
the weather along the planned route (including takeoff and landing)
allows flight under VFR under the ceiling (if a ceiling exists) and
that the weather is forecast to remain so until at least 1 hour after
the estimated time of arrival at the destination, a person may operate
an aircraft over-the-top.
* * * * *
Sec. 135.411 [Amended]
7. Section 135.411 is amended by adding paragraph (c) to read as
follows:
* * * * *
(c) Single engine aircraft used in passenger-carrying IFR
operations shall also be maintained in accordance with Sec. 135.421
(c), (d), and (e).
8. Section 135.421 is amended by adding paragraph (c), (d), and (e)
to read as follows:
Sec. 135.421 Additional maintenance requirements.
* * * * *
(c) For each single engine aircraft to be used in passenger-
carrying IFR operations, each certificate holder must incorporate into
its maintenance program either:
(1) the manufacturer's recommended engine trend monitoring program,
which includes an oil analysis, if appropriate, or
(2) an FAA approved engine trend monitoring program that includes
an oil analysis at each 100 hour interval or at the manufacturer's
suggested interval, whichever is more frequent.
(d) For single engine aircraft to be used in passenger-carrying IFR
operations, written maintenance instructions containing the methods,
techniques, and practices necessary to maintain the equipment specified
in Secs. 135.105, and 135.163 (f) and (h) are required.
(e) No certificate holder may operate a single engine aircraft
under IFR, carrying passengers, unless the certificate holder records
and maintains in the engine maintenance records the results of each
test, observation, and inspection required by the applicable engine
trend monitoring program specified in (c) (1) and (c) (2) of this
section.
Issued in Washington, DC on July 31, 1997.
Barry L. Valentine,
Acting Administrator.
[FR Doc. 97-20641 Filed 8-1-97; 11:49 am]
BILLING CODE 4910-13-M
