[Federal Register Volume 61, Number 13 (Friday, January 19, 1996)]
[Proposed Rules]
[Pages 1303-1306]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-485]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 90-CE-61-AD]
Airworthiness Directives; The New Piper Aircraft, Inc. (Formerly
Piper Aircraft Corporation) Models PA31T, PA31T1, PA31T2, and PA31T3
Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: This document proposes to supersede Airworthiness Directive
(AD) 84-08-06, which currently requires the following on certain The
New Piper Aircraft, Inc. (Piper) Models PA31T, PA31T1, PA31T2, and
PA31T3 airplanes: repetitively inspecting the fuselage station (FS) 332
bulkhead for cracks, and reinforcing or replacing the FS 332 bulkhead
if cracks are found. The Federal Aviation Administration's policy on
aging commuter-class aircraft is to eliminate or, in certain instances,
reduce the number of certain repetitive short-interval inspections when
improved parts or modifications are available. The proposed action
would retain the current repetitive inspections contained in AD 84-08-
06, and would require incorporating a stabilizer forward spar
attachment bulkhead reinforcement kit or installing a reinforced
bulkhead assembly as terminating action for the repetitive inspection
requirement. The actions specified in the proposed AD are intended to
prevent structural failure of the horizontal stabilizer and the aft
fuselage attachment caused by cracks in the FS 332 bulkhead, which, if
not detected and corrected, could result in loss of control of the
airplane.
DATES: Comments must be received on or before March 23, 1996.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Central Region, Office of the Assistant Chief
Counsel, Attention: Rules Docket No. 90-CE-61-AD, Room 1558, 601 E.
12th Street, Kansas City, Missouri 64106. Comments may be inspected at
this location between 8 a.m. and 4 p.m., Monday through Friday,
holidays excepted.
Service information that relates to the proposed AD may be obtained
from The New Piper Aircraft, Inc., Customer Services, 2926 Piper Drive,
Vero Beach, Florida 32960. This information also may be examined at the
Rules Docket at the address above.
FOR FURTHER INFORMATION CONTACT: Christina Marsh, Aerospace Engineer,
FAA, Atlanta Aircraft Certification Office, Campus Building, 1701
Columbia Avenue, suite 2-160, College Park, Georgia 30337-2748;
telephone (404) 305-7362; facsimile (404) 305-7348.
SUPPLEMENTARY INFORMATION:
Comments Invited
Interested persons are invited to participate in the making of the
proposed rule by submitting such written data, views, or arguments as
they may desire. Communications should identify the Rules Docket number
and be submitted in triplicate to the address specified above. All
communications received on or before the closing date for comments,
specified above, will be considered before taking action on the
proposed rule. The proposals contained in this notice may be changed in
light of the comments received.
Comments are specifically invited on the overall regulatory,
economic, environmental, and energy aspects of the proposed rule. All
comments submitted will be available, both before and after the closing
date for comments, in the Rules Docket for examination by interested
persons. A report that summarizes each FAA-public contact concerned
with the substance of this proposal will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments
submitted in response to this notice must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket No. 90-CE-61-AD.'' The postcard will be date stamped and
returned to the commenter.
[[Page 1304]]
Availability of NPRMs
Any person may obtain a copy of this NPRM by submitting a request
to the FAA, Central Region, Office of the Assistant Chief Counsel,
Attention: Rules Docket No. 90-CE-61-AD, Room 1558, 601 E. 12th Street,
Kansas City, Missouri 64106.
Discussion
The FAA has determined that reliance on critical repetitive
inspections on aging commuter-class airplanes carries an unnecessary
safety risk when a design change exists that could eliminate or, in
certain instances, reduce the number of those critical inspections. In
determining what inspections are critical, the FAA considers (1) the
safety consequences if the known problem is not detected during the
inspection; (2) the probability of the problem not being detected
during the inspection; (3) whether the inspection area is difficult to
access; and (4) the possibility of damage to an adjacent structure as a
result of the problem.
These factors have led the FAA to establish an aging commuter-class
aircraft policy that requires incorporating a known design change when
it could replace a critical repetitive inspection. With this policy in
mind, the FAA conducted a review of existing AD's that apply to Piper
Models PA31-350 and PA31T3 airplanes. Assisting the FAA in this review
were (1) The New Piper Aircraft, Inc.; (2) the Regional Airlines
Association (RAA); and (3) several operators of the affected airplanes.
From this review, the FAA has identified AD 84-08-06, Amendment 39-
4851, as one that should be superseded with a new AD that would require
a modification that would eliminate the need for short-interval and
critical repetitive inspections. AD 84-08-06 currently requires the
following on Piper Models PA31T, PA31T1, PA31T2, and PA31T3 airplanes:
--Repetitively inspecting the fuselage station (FS) 332 bulkhead for
cracks, reinforcing the FS 332 bulkhead (Piper Kit 764-983) if all
cracks found do not exceed certain limits, and replacing the bulkhead
assembly with a reinforced replacement bulkhead assembly (part number
45583-16 or 45583-17) if any crack is found that exceeds certain
limits. Accomplishment of the inspections required by AD 84-08-06 is in
accordance with Piper Service Bulletin (SB) No. 773, dated December 19,
1983; and
--Allowing for the provision of incorporating Piper Kit 764-983 or part
number 45583-16 or 45583-17 bulkhead assembly as terminating action for
the repetitive inspection requirement. The incorporation of Piper Kit
764-983 is accomplished in accordance with the instructions provided
with the kit, and the reinforced bulkhead assembly installations are
accomplished in accordance with the applicable maintenance manual.
Based on its aging commuter-class aircraft policy and after
reviewing all available information related to this subject including
the referenced service information, the FAA has determined that AD
action should be taken to eliminate the repetitive short-interval
inspections required by AD 84-08-06, and to prevent structural failure
of the horizontal stabilizer and the aft fuselage attachment caused by
cracks in the FS 332 bulkhead, which, if not detected and corrected,
could result in loss of control of the airplane.
Since an unsafe condition has been identified that is likely to
exist or develop in other Piper Models PA31T, PA31T1, PA31T2, and
PA31T3 airplanes of the same type design, the proposed AD would
supersede AD 84-08-06 with a new AD that would (1) retain the
requirement of repetitively inspecting the FS 332 bulkhead for cracks,
reinforcing the FS 332 bulkhead (Piper Kit 764-983) if any crack is
found that does not exceed certain limits, and replacing the bulkhead
assembly with a reinforced bulkhead assembly (part number 45583-16 or
45583-17) if any crack is found that exceeds certain limits; and (2)
require incorporating a stabilizer forward spar attachment bulkhead
reinforcement (Piper Kit 764-983) or a reinforced bulkhead assembly
(part number 45583-16 or 45583-17) as terminating action for the
repetitive inspections. Accomplishment of the proposed inspections
would be in accordance with Piper SB No. 773A, dated May 3, 1984. The
incorporation of Piper Kit 764-983 would be accomplished in accordance
with the instructions to this kit (Revised June 18, 1990), and the
reinforced bulkhead installations would be accomplished in accordance
with the applicable maintenance manual.
The FAA estimates that 736 airplanes in the U.S. registry would be
affected by the proposed AD, that it would take approximately 60
workhours per airplane to accomplish the proposed replacement, and that
the average labor rate is approximately $60 an hour. Parts cost
approximately $782 per airplane. Based on these figures, the total cost
impact of the proposed AD on U.S. operators is estimated to be
$3,225,152 or $4,382 per airplane. This figure is based on the
assumption that no affected airplane owner/operator has accomplished
the proposed replacement.
Piper has informed the FAA that parts have been distributed to
enough owners/operators to equip 348 of the affected airplanes.
Assuming that each set of parts has been installed on an affected
airplane, the cost impact of the proposed AD upon U.S. owners operators
of the affected airplanes would be reduced by $1,524,936 from
$3,225,152 to $1,700,216.
The intent of the FAA's aging commuter airplane program is to
ensure safe operation of commuter-class airplanes that are in
commercial service without adversely impacting private operators. The
FAA believes that a large number of the remaining 388 affected
airplanes (736 affected airplanes--348 sets of parts distributed) that
would be affected by the proposed modification AD are operated in
various types of air transportation. This includes scheduled passenger
service, air cargo, and air taxi.
The proposed AD allows 600 hours time-in-service (TIS) after the
effective date of the proposed AD before mandatory accomplishment of
the design modification. The average utilization of the fleet for those
airplanes in air transportation is between 25 to 40 hours TIS per week.
Based on these figures, operators of commuter-class airplanes involved
in commercial operation would have to accomplish the proposed
modification within four to six months after the proposed AD would
become effective. For private owners, who typically operate between 100
to 200 hours TIS per year, this would allow three to six years before
the proposed modification would be mandatory.
The FAA established the 600 hours TIS replacement compliance time
based on its engineering evaluation of the problem. Among the issues
looked at in this engineering evaluation were analysis of service
difficulty reports, the difficulty level of the inspection, and how
critical the situation would be if cracks occurred in the subject area
despite accomplishment of the repetitive inspections.
Usually, the FAA establishes the mandatory design modification
compliance time on AD's affecting aging commuter-class airplanes upon
the accumulation of a certain number of hours TIS on the airplane. For
this action, the FAA is proposing to mandate the modification for all
operators
[[Page 1305]]
``within the next 600 hours TIS after the effective date of this AD.''
The total TIS levels of the airplane fleet vary from under 1,000 hours
TIS to over 5,000 hours TIS, and annual accumulation rates vary from 50
hours TIS to over 1,000 hours TIS. Establishing a long-term set
compliance time of hours TIS accumulated on Piper Models PA31T, PA31T1,
PA31T2, and PA31T3 airplanes (such as 5,000 hours TIS) would impose the
undue burden on the manufacturer of having to maintain a supply of
replacement parts for the entire fleet when many airplanes in the fleet
may never reach this compliance time.
Instead, the FAA believes that Piper should maintain parts for
several years; in this case about six years to allow low-usage
airplanes time to accumulate the 600 hours after the effective date of
the AD. The FAA has determined that the compliance time of the proposed
rule provides the level of safety required for commuter air service
while still minimizing the impact on the private airplane owners of
Piper Models PA31T, PA31T1, PA31T2, and PA31T3 airplanes.
The regulations proposed 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 12612, it is determined that this
proposal would not have sufficient federalism implications to warrant
the preparation of a Federalism Assessment.
For the reasons discussed above, I certify that this action (1) is
not a ``significant regulatory action'' under Executive Order 12866;
(2) is not a ``significant rule'' under DOT Regulatory Policies and
Procedures (44 FR. 11034, February 26, 1979); and (3) if promulgated,
will not have a significant economic impact, positive or negative, on a
substantial number of small entities under the criteria of the
Regulatory Flexibility Act. A copy of the draft regulatory evaluation
prepared for this action has been placed in the Rules Docket. A copy of
it may be obtained by contacting the Rules Docket at the location
provided under the caption ADDRESSES.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Safety.
The Proposed Amendment
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration proposes to amend
part 39 of the Federal Aviation Regulations (14 CFR part 39) as
follows:
PART 39--AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority: 49 USC 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by removing Airworthiness Directive
(AD) 84-08-06, Amendment 39-4851, and by adding a new AD to read as
follows:
The New Piper Aircraft, Inc. (formerly Piper Aircraft Corporation):
Docket No. 90-CE-61-AD. Supersedes AD 84-08-06, Amendment 39-4851.
Applicability: The following model and serial number airplanes,
certificated in any category, that do not have either Piper Kit 764-
983 (stabilizer forward spar attachment bulkhead reinforcement)
incorporated at Fuselage Station (FS) 332 or have a part number (P/
N) 45583-16 or P/N 45583-17 bulkhead assembly installed:
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Models Serial No.
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PA31T............................ 31T-7400002 through 31T-8120104.
PA31T1........................... 31T-7804001 through 31T-8104101, 31T-
8304003, and 31T-1104004 through 31T-
1104007.
PA31T2........................... 31T-8166001 through 31T-8166032, 31T-
8166034 through 31T-8166065, 31T-
8166067 through 31T-8166071, and 31T-
8166073 through 31T-8166075.
PA31T3........................... 31T-8275001, 31T-8275003 through 31T-
8275012, 31T-8275014 through 31T-
8275017, 31T-8275025, and 31T-
8375001 through 31T-8375005.
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Note 1: This AD applies to each airplane identified in the
preceding applicability provision, regardless of whether it has been
modified, altered, or repaired in the area subject to the
requirements of this AD. For airplanes that have been modified,
altered, or repaired so that the performance of the requirements of
this AD is affected, the owner/operator must request approval for an
alternative method of compliance in accordance with paragraph (h) of
this AD. The request should include an assessment of the effect of
the modification, alteration, or repair on the unsafe condition
addressed by this AD; and, if the unsafe condition has not been
eliminated, the request should include specific proposed actions to
address it. Compliance: Required as indicated in the body of this
AD, unless already accomplished.
To prevent structural failure of the horizontal stabilizer and
the aft fuselage attachment caused by cracks in the FS 332 bulkhead,
which, if not detected and corrected, could result in loss of
control of the airplane, accomplish the following:
(a) Within the next 200 hours time-in-service (TIS) after the
effective date of this AD, unless already accomplished (compliance
with AD 84-08-06), and thereafter at intervals not to exceed 200
hours TIS until the modification required by paragraph (c), (d), or
(e) of this AD is incorporated, inspect (using dye penetrant
methods) the FS 332 bulkhead for cracks. Accomplish the inspections
in accordance with the INSTRUCTIONS section of Piper Service
Bulletin No. 773A, dated May 3, 1984.
(b) The initial dye penetrant inspection type must be utilized
for all future repetitive inspections. Dye penetrant inspection
types consist of Type I: fluorescent; Type II: non-fluorescent or
visible dye; and Type III: dual sensitivity.
(c) If cracks are found during any of the inspections required
in paragraph (a) of this AD and no crack exceeds the limitations
specified in Piper SB No. 773A, dated May 3, 1984, prior to further
flight, repair the cracks in accordance with Piper SB No. 773A,
dated May 3, 1984, and reinforce the FS 332 bulkhead by
incorporating Piper Kit 764-983 in accordance with the instructions
to Piper Kit 764-983, Revised June 18, 1990.
(d) If cracks are found during any of the inspections required
in paragraph (a) of this AD and any crack exceeds the limitations
specified in Piper SB No. 773A, dated May 3, 1984, prior to further
flight, replace the bulkhead assembly with a reinforced bulkhead
assembly, P/N 45583-16 or P/N 45583-17. Accomplish this replacement
in accordance with the applicable maintenance manual.
(e) Upon the accomplishment of the third repetitive inspection
required by this AD (600 hours TIS after the effective date of this
AD), unless already accomplished as required by paragraph (c) or (d)
of this AD, accomplish one of the following, as applicable:
(1) If cracks are found and no crack exceeds the limitations
specified in Piper SB No. 773A, dated May 3, 1984, repair the cracks
in accordance with Piper SB No. 773A, dated May 3, 1984, and
reinforce the FS 332 bulkhead by incorporating Piper Kit 764-983 in
accordance with the instructions to Piper Kit 764-983, Revised June
18, 1990;
(2) If cracks are found and any crack exceeds the limitations
specified in Piper SB No. 773A, dated May 3, 1984, replace the
bulkhead assembly with a reinforced bulkhead assembly, P/N 45583-16
or P/N 45583-17, in accordance with the applicable maintenance
manual; or
(3) If no cracks are found, either reinforce the FS 332 bulkhead
by incorporating Piper Kit 764-983 in accordance with the
instructions to Piper Kit 764-983, Revised June 18, 1990; or replace
the bulkhead assembly with a reinforced bulkhead assembly, P/N
45583-16 or P/N 45583-17, in accordance with the applicable
maintenance manual.
(f) Incorporating Piper Kit 764-983 or installing reinforced
bulkhead assembly, P/N 45583-16 or P/N 45583- 17, as required by
paragraphs (c) and (d) or (e) of this AD is considered terminating
action for the repetitive inspection requirement of this AD.
[[Page 1306]]
(g) Special flight permits may be issued in accordance with
sections 21.197 and 21.199 of the Federal Aviation Regulations (14
CFR 21.197 and 21.199) to operate the airplane to a location where
the requirements of this AD can be accomplished.
(h) An alternative method of compliance or adjustment of the
compliance time that provides an equivalent level of safety may be
approved by the Manager, Atlanta Aircraft Certification Office
(ACO), Campus Building, 1701 Columbia Avenue, suite 2-160, College
Park, Georgia 30337-2748. The request shall be forwarded through an
appropriate FAA Maintenance Inspector, who may add comments and then
send it to the Manager, Atlanta ACO.
Note 2: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Atlanta ACO.
Note 3: Alternative methods of compliance approved in accordance
with AD 84-08-06 (superseded by this action) are not considered
approved as alternative methods of compliance with this AD.
(i) All persons affected by this directive may obtain copies of
the document referred to herein upon request to The New Piper
Aircraft, Inc., 2926 Piper Drive, Vero Beach, Florida 32960; or may
examine this document at the FAA, Central Region, Office of the
Assistant Chief Counsel, Room 1558, 601 E. 12th Street, Kansas City,
Missouri 64106.
(j) This amendment supersedes AD 84-08-06, Amendment 39-4851.
Issued in Kansas City, Missouri, on January 10, 1996.
Michael Gallagher,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 96-485 Filed 1-18-96; 8:45 am]
BILLING CODE 4910-13-U
