[Federal Register Volume 60, Number 235 (Thursday, December 7, 1995)]
[Proposed Rules]
[Pages 62774-62776]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-29858]



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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 90-CE-59-AD]


Airworthiness Directives; The New Piper Aircraft, Inc. (Formerly 
Piper Aircraft Corporation) Models PA31, PA31-325, PA31-350, PA31P, 
PA31T1, and PA31T 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) 80-26-05, which currently requires the following on The New Piper 
Aircraft, Inc. (Piper) Models PA31, PA31-325, PA31-350, PA31P, PA31T1, 
and PA31T airplanes: repetitively inspecting the main landing gear 
(MLG) inboard door hinges and attachment angles for cracks, and 
replacing any cracked MLG inboard door hinge or attachment angle. 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 80-26-05, and would 
require incorporating a MLG inboard door hinge and attachment angle 
assembly of improved design (part number 47529-32) or approved hinges 
and angles made of steel as terminating action for the repetitive 
inspection requirement. The actions specified in the proposed AD are 
intended to prevent separation of the inboard MLG door from the 
airplane caused by a cracked inboard door hinge or attachment angle, 
which, if not detected and corrected, could result in the MLG jamming 
and loss of control of the airplane during landing operations.

DATES: Comments must be received on or before February 21, 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-59-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-59-AD.'' The postcard will be date stamped and 
returned to the commenter.

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-59-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. 


[[Page 62775]]

    From this review, the FAA has identified AD 80-26-05, Amendment 39-
3994, 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 80-26-05 currently requires the 
following on Piper Models PA31, PA31-325, PA31-350, PA31P, PA31T1, and 
PA31T airplanes:

--Repetitively inspecting the main landing gear (MLG) inboard door 
hinges and attachment angles for cracks, and replacing any cracked MLG 
inboard door hinge or attachment angle. Accomplishment of the 
inspections required by AD 80-26-05 is in accordance with Piper Service 
Bulletin (SB) No. 682, dated July 24, 1980; and
--Allowing for the provision of installing inboard door hinges and 
attachment angles made of steel as terminating action for the 
repetitive inspections.

    Piper SB No. 682, dated July 24, 1980, references a new improved 
door hinge assembly, part number (P/N) 47529-32, which, when 
incorporated, provides terminating action for the repetitive 
inspections of the MLG inboard door hinge and attachment angles. Piper 
SB No. 682 contains procedures for incorporating this new improved door 
hinge assembly.
    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 80-26-05, and to prevent separation of a MLG 
door from the airplane caused by a cracked inboard door hinge or 
attachment angle, which, if not detected and corrected, could result in 
the MLG jamming and loss of control of the airplane during landing 
operations.
    Since an unsafe condition has been identified that is likely to 
exist or develop in other Piper Models PA31, PA31-325, PA31-350, PA31P, 
PA31T1, and PA31T airplanes of the same type design, the proposed AD 
would supersede AD 80-26-05 with a new AD that would (1) retain the 
requirement of repetitively inspecting the MLG inboard door hinges and 
attachment angles for cracks, and replacing any cracked MLG inboard 
door hinge or attachment angle; and (2) require incorporating a MLG 
inboard door hinge and attachment angle assembly of improved design 
(part number 47529-32) or FAA-approved hinges and angles made of steel 
as terminating action for the repetitive inspection requirement. 
Accomplishment of the proposed inspections would be in accordance with 
Piper SB No. 682, dated July 24, 1980.
    The FAA estimates that 2,448 airplanes in the U.S. registry would 
be affected by the proposed AD, that it would take approximately 2 
workhours per airplane to accomplish the proposed replacement, and that 
the average labor rate is approximately $60 an hour. Parts cost 
approximately $1,664 per airplane ($416 per assembly  x 4 assemblies 
per airplane). Based on these figures, the total cost impact of the 
proposed AD on U.S. operators is estimated to be $4,367,232 or $1,784 
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 hinge assemblies have been 
distributed to equip approximately 400 (1,600 separate assemblies) of 
the affected airplanes. Assuming that 400 of the affected airplanes 
have four of these hinge assemblies incorporated, the cost impact of 
the proposed AD upon U.S. owners operators of the affected airplanes 
would be reduced by $713,600 from $4,367,232 to $3,653,632.
    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 2,048 affected 
airplanes (2,448 affected airplanes--400 airplanes) that would be 
affected by the proposed AD are operated in various types of air 
transportation. This includes scheduled passenger service, air cargo, 
and air taxi.
    The proposed AD would allow 800 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 5 to 8 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 4 to 8 years before the proposed 
modification would be mandatory.
    The FAA established the 800 hours TIS replacement compliance time 
based on its engineering evaluation of the problem. Among the issues 
examined 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 ``within the next 800 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 PA31, 
PA31-325, PA31-350, PA31P, PA31T1, and PA31T airplanes (such as 5,000 
hours TIS) would impose an 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 8 years to allow low-usage airplanes 
time to accumulate the 800 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 PA31, PA31-325, PA31-350, PA31P, PA31T1, and PA31T 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 

[[Page 62776]]
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), 40101, 40113, 44701.


Sec.  39.13  [Amended]

    2. Section 39.13 is amended by removing Airworthiness Directive 
(AD) 80-26-05, Amendment 39- 3994, and by adding a new AD to read as 
follows:

The New Piper Aircraft, Inc. (formerly Piper Aircraft Corporation): 
Docket No. 90-CE-59-AD. Supersedes AD 80-26-05, Amendment 39-3994.

    Applicability: The following model and serial number airplanes, 
certificated in any category, that are not equipped with Piper part 
number (P/N) 47529-32 door hinge assemblies or FAA-approved inboard 
door hinges and attachment angles made of steel at all four hinge 
assembly locations:

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               Models                             Serial Nos.           
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PA31 and PA31-325...................  31-2 through 31-8012077.          
PA31-350............................  31-5001 through 31-8052168.       
PA31P...............................  31P-3 through 31P-7730012.        
PA-31T1.............................  31T-7804001 through 31T-8004040.  
PA-31T..............................  31T-7400002 through 31T-8020076.  
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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 (g) 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 separation of a main landing gear (MLG) door from the 
airplane caused by a cracked inboard door hinge or attachment angle, 
which, if not detected and corrected, could result in the MLG 
jamming and loss of control of the airplane during landing 
operations, accomplish the following:
    (a) Within the next 100 hours time-in-service (TIS) after the 
effective date of this AD, unless already accomplished (compliance 
with AD 80-26-05), and thereafter at intervals not to exceed 100 
hours TIS until the modification required by paragraph (c) or (d) of 
this AD is incorporated, inspect (using dye penetrant methods) the 
MLG inboard door hinges and attachment angles for cracks. Accomplish 
the inspections in accordance with the INSTRUCTIONS section of Piper 
Service Bulletin No. 682, dated July 24, 1980.
    (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, prior to further flight, incorporate a 
Piper P/N 47529-32 MLG inboard door hinge and attachment angle 
assembly or install FAA-approved hinges and angles made of steel.
    (d) Within the next 800 hours TIS after the effective date of 
this AD, unless already accomplished as required by paragraph (c) of 
this AD, incorporate a Piper P/N 47529-32 MLG inboard door hinge and 
attachment angle assembly or install FAA-approved hinges and angles 
made of steel in all four hinge assembly locations.
    (e) Incorporating a Piper P/N 47529-32 MLG inboard door hinge 
and attachment angle assembly or installing FAA-approved hinges and 
angles made of steel in all four assembly locations as required by 
paragraphs (c) and (d) of this AD is considered terminating action 
for the repetitive inspection requirement of this AD.
    (f) 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.
    (g) 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 80-26-05 (superseded by this action) are not considered 
approved as alternative methods of compliance with this AD.

    (h) 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.
    (i) This amendment supersedes AD 80-26-05, Amendment 39-3994.

    Issued in Kansas City, Missouri, on December 1, 1995.
John R. Colomy,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 95-29858 Filed 12-6-95; 8:45 am]
BILLING CODE 4910-13-U