[Federal Register Volume 65, Number 243 (Monday, December 18, 2000)]
[Rules and Regulations]
[Pages 78902-78905]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-31451]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 96-CE-69-AD; Amendment 39-12035; AD 2000-25-01]
RIN 2120-AA64


Airworthiness Directives; The New Piper Aircraft, Inc. (formerly 
Piper Aircraft Corporation) PA-31 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment supersedes Airworthiness Directive (AD) 80-26-
05, which currently requires you to repetitively inspect the main 
landing gear (MLG) inboard door hinges and attachment angles for cracks 
on certain The New Piper Aircraft, Inc. (Piper) PA-31 series airplanes. 
AD 80-26-05 also requires you to replace any cracked MLG inboard door 
hinge or attachment angle with parts of improved design. This AD 
results from the Federal Aviation Administration's policy on aging 
commuter-class aircraft and the determination that an improved design 
MLG inboard door hinge and attachment assembly, when incorporated, will 
eliminate the need for the currently required repetitive short-interval 
inspections; however, we have received reports of cracks in the 
improved design MLG inboard door hinge assemblies on the affected 
airplanes. This AD retains the current repetitive inspections contained 
in AD 80-26-05, and requires inspections on the improved design parts. 
The actions specified by this AD are intended to detect and correct 
cracked MLG inboard door hinge assemblies. These cracked door hinge 
assemblies could result in the MLG becoming jammed, with consequent 
loss of control of the airplane during landing operations.

DATES: This AD becomes effective on January 19, 2001.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in the regulations as of 
January 19, 2001.

ADDRESSES: You may get the service information referenced in this AD 
from The New Piper Aircraft, Inc., Customer Services, 2926 Piper Drive, 
Vero Beach, Florida 32960. You may examine this information at the 
Federal Aviation Administration (FAA), Central Region, Office of the 
Regional Counsel, Attention: Rules Docket No. 96-CE-69-AD, 901 Locust, 
Room 506, Kansas City, Missouri 64106; or at the Office of the Federal 
Register, 800 North Capitol Street, NW, suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: William O. Herderich, Aerospace 
Engineer, FAA, Atlanta Aircraft Certification Office, One Crown Center, 
1895 Phoenix Boulevard, suite 450, Atlanta, Georgia 30349; telephone: 
(770) 703-6082; facsimile: (770) 703-6097; e-mail: 
[email protected].

SUPPLEMENTARY INFORMATION:

Discussion

    What prior AD action did FAA take on this subject? In 1980, FAA 
issued AD 80-26-05, Amendment 39-3994, in order to detect and correct 
cracked main landing gear (MLG) inboard door hinge assemblies on 
certain Piper PA-31 series airplanes. AD 80-26-05 currently requires 
you to repetitively inspect the MLG inboard door hinges and attachment 
angles for cracks; and requires you to replace any cracked MLG inboard 
door hinge or attachment angle.
    On December 1, 1995, we issued a proposal to amend part 39 of the 
Federal Aviation Regulations (14 CFR part 39) to include an AD that 
would apply to certain Piper PA-31 series airplanes. This proposal was 
published in the Federal Register as a notice of proposed rulemaking 
(NPRM) on December 7, 1995 (60 FR 62774), and proposed to supersede AD 
80-26-05, Amendment 39-3994. The NPRM proposed to:

--Retain the requirement of repetitively inspecting the MLG inboard 
door hinge assemblies for cracks, and replacing any cracked MLG inboard 
door hinge assembly; and
--Require incorporating a MLG inboard door hinge assembly of improved 
design (part number (P/N) 47529-32) or FAA-approved equivalent part 
number, as terminating action for the repetitive inspection 
requirement.

    Accomplishment of the proposed inspections would have been required 
in accordance with Piper Service Bulletin (SB) No. 682, dated July 24, 
1980.
    This NPRM was consistent with FAA's aging commuter-class aircraft 
policy, which briefly states that, when a modification exists that 
could eliminate or reduce the number of required critical inspections, 
the modification should be incorporated. This policy is based on FAA's 
determination 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. The alternative to 
installing the improved design hinge assemblies on the affected 
airplanes would be to rely on the repetitive inspections required by AD 
80-26-05 to detect cracks in these areas.
    Was the public invited to comment on the NPRM? The FAA invited 
interested persons to participate in the making of this amendment. Due 
consideration was given to the one comment received.
    What issue did this comment address? The comment received on the 
NPRM contained information that the improved design MLG inboard door 
hinge assemblies, P/N 47529-32, are also susceptible to fatigue 
cracking, and that installing this assembly should not eliminate the 
need for the repetitive inspections currently required by AD 80-26-05. 
The commenter stated that its airplane fleet has experienced three 
failures and three incidents related to fatigue cracking of the P/N 
47529-32 hinge assemblies.
    What action did FAA take? We conducted a review of the 
manufacturer's service history and service difficulty reports in FAA's 
database associated with the P/N 47529-32 MLG inboard door hinge 
assembly. Based on a review of this information, including the 
information received from the commenter, we determined that more 
information and analysis were needed before mandating MLG inboard door 
hinge assembly replacements through an AD.
    We then issued an advance notice of proposed rulemaking (ANPRM) on 
February 11, 1997. The ANPRM was published in the Federal Register on 
February 19, 1997 (62 FR 7375). The purpose of the ANPRM was to 
encourage interested persons to provide information that describes what 
they consider the best action (if any) for FAA to take regarding the P/
N 47529-32 MLG inboard door hinge assembly issue. The FAA also withdrew 
the NPRM. We received no information or comments regarding the ANPRM.
    We then re-evaluated the information in our service difficulty 
database. The database, at that time, contained 10 reports of failure 
or cracks found in the MLG inboard door hinge assembly on the affected 
airplanes. The commenter to the original NPRM had submitted six

[[Page 78903]]

of these reports. Three of these six incident reports were specifically 
attributed to the original MLG inboard door hinge assemblies and three 
to the improved design MLG inboard door hinge assemblies. The four 
reports that others submitted do not specifically identify whether the 
original MLG inboard door hinge assemblies were installed or the 
improved design assemblies were installed. Since the incidents occurred 
on high service time airplanes and since there is no AD action 
mandating the installation of the improved-design MLG inboard door 
hinge assemblies, we presumed that the original hinge assemblies were 
installed.
    The FAA then reviewed the three incident reports on the improved 
design MLG inboard door hinge assemblies and, along with the National 
Transportation Safety Board (NTSB), performed extensive testing and 
analysis of the improved design MLG inboard door hinge assemblies. 
Based on this review, testing, and analysis, we determined that:

--The incidents were isolated and that mandating repetitive inspections 
was not needed when the P/N 47529-32 MLG inboard door hinge assemblies 
are installed; and
--AD action should be taken to eliminate the repetitive short-interval 
inspections that AD 80-26-05 requires and to prevent separation of a 
MLG door from the airplane caused by a cracked inboard door hinge 
assembly.

    On October 14, 1997, FAA issued an NPRM to address these issues. 
The NPRM was published in the Federal Register on October 21, 1997 (62 
FR 54595).
    What has happened to justify this AD action? Since issuance of the 
NPRM, we have received additional reports of cracks in the MLG inboard 
door hinge assemblies. The reports reference incidents on both the 
original design assemblies and the improved design hinges. As of the 
issue date of this document, we have reports of the following:

--27 reports of cracked improved design MLG inboard door hinge 
assemblies; and
--41 reports of cracked original design MLG inboard door hinge 
assemblies.

    We issued a proposal to amend part 39 of the Federal Aviation 
Regulations (14 CFR part 39) to include an AD that would apply to 
certain Piper PA-31 series airplanes. This proposal was published in 
the Federal Register as a supplemental NPRM on July 21, 2000 (65 FR 
45323). The supplemental NPRM proposed to supersede AD 80-26-05, 
Amendment 39-3994, with a new AD that proposed to require:

--Repetitively inspecting the MLG inboard door hinge assemblies 
(regardless of part number); and
--Immediately replacing any cracked MLG inboard door hinge assembly 
with a new MLG inboard door hinge assembly, Piper part number (P/N) 
47529-32 (or FAA-approved equivalent part number).

    What is the potential impact if FAA took no action? These actions 
are necessary to detect and correct cracked MLG inboard door hinge 
assemblies. These cracked door hinge assemblies could result in the MLG 
becoming jammed with consequent loss of control of the airplane during 
landing operations.
    Was the public invited to comment? The FAA encouraged interested 
persons to participate in the making of this amendment. The following 
presents the comments received on the proposal and FAA's response to 
each comment:

Comment Issue No. 1: Piper Part Number (P/N) 47529-32 MLG Door 
Hinge Assemblies Are Not Made of Steel

    What is the commenter's concern? The commenter states that the NPRM 
incorrectly identifies the Piper P/N 47529-32 MLG door hinge assemblies 
as parts made of steel. The commenter explains that these assemblies 
are made of aluminum.
    What is FAA's response to the concern? We concur that the Piper P/N 
47529-32 MLG door hinge assemblies are made of aluminum. We 
inadvertently referenced these parts as steel parts in the supplemental 
NPRM.
    We are changing the final rule AD accordingly.

Comment Issue No. 2: All MLG Door Hinge Assemblies Should Be 
Inspected at 100-Hour TIS Intervals

    What is the commenter's concern? The commenter expresses doubt that 
the Piper P/N 47529-32 MLG door hinge assemblies can go as long as 
2,000-hour TIS intervals between inspections before cracking. The 
commenter recommends 100-hour TIS interval inspections for these 
assemblies.
    What is FAA's response to the concern? We determined that the 
2,000-hour TIS interval was an adequate compliance time for these parts 
based on our conservative estimate of all quantitative information 
available. The service reports indicate failures on airplanes ranging 
from a low of 3,615 total hours TIS to a high of 14,852 total hours 
TIS.
    We are not changing the final rule AD as a result of this comment.

Comment Issue No. 3: FAA Underestimated the Cost Impact

    What is the commenter's concern? The commenter states that the cost 
impact presented in the supplemental NPRM is incorrect because:

--Removal of the hinges provides the most practical method of 
fluorescent dye-penetrant inspections and this would raise the 
inspections costs from $120 to $500; and
--The cost of Piper P/N 47-528-32 MLG door hinge assemblies is 
approximately $465 instead of $270 as specified in the supplemental 
NPRM.

    What is FAA's response to the concern? We do not concur with 
changing the cost to accomplish the inspection. While removing the 
hinges from the airplane to accomplish the inspection is an option, FAA 
has determined that you can adequately accomplish the inspections 
without removing the hinges.
    After checking with the manufacturer, we concur that the cost for 
the replacement MLG door hinge assemblies is approximately $465.
    We are changing the Cost Impact section of this document 
accordingly.

Comment Issue No. 4: AD Should Not Apply to MLG Door Hinge 
Assemblies That Are Made of Steel

    What is the commenter's concern? The commenter states that the AD 
should follow Piper Service Bulletin No. 682 and not require 
inspections on airplanes that have MLG door hinge assemblies that are 
made of steel. The commenter also requests that FAA include a list of 
the two outside sources that currently provide assemblies made of 
steel.
    What is FAA's response to the concern? We concur that the AD should 
not apply to MLG door hinge assemblies that are made of steel and we 
are changing the final rule accordingly.
    However, FAA is not including the list of those outside sources 
that currently provide assemblies made of steel. If we did include this 
list, out of fairness, we would feel obligated to revise the AD anytime 
an outside source developed and received approval for installation of 
MLG door hinge assemblies made of steel on the affected airplanes.
    A list of outside vendors with FAA-approved assemblies made of 
steel is always available from the FAA address included in the AD.

[[Page 78904]]

The FAA's Determination

    What is FAA's final determination on this issue? We carefully 
reviewed all available information related to the subject presented 
above and determined that air safety and the public interest require 
the adoption of the rule as proposed except for the changes discussed 
above and editorial corrections. These changes and corrections provide 
the intent that was proposed in the supplemental NPRM for correcting 
the unsafe condition and do not impose any additional burden than what 
was intended in the supplemental NPRM.

Cost Impact

    How many airplanes does this AD impact? We estimate that this AD 
affects 2,344 airplanes in the U.S. registry.
    What is the cost impact of this AD on owners/operators of the 
affected airplanes? We estimate the following costs to accomplish the 
initial inspection:

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                                                                                                      Total cost
                                                                                                       on U.S.
                Labor cost                          Parts cost            Total cost per airplane      airplane
                                                                                                      operators
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2 workhours  x  $60 per hour = $120......  No parts required for the    $120 per airplane..........     $281,280
                                            inspection.
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    We estimate the following costs to accomplish the replacement, if 
necessary:

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               Labor cost                        Parts cost                    Total cost per airplane
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2 workhours  x  $60 per hour = $120....  $465 per airplane.........  $585 per airplane.
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Regulatory Impact

    Does this AD impact various entities? The regulations adopted 
herein will not have a substantial direct effect 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, it is determined that this final rule does not 
have federalism implications under Executive Order 13132.
    Does this AD involve a significant rule or regulatory action? 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) 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 final evaluation prepared for this action is contained 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, Incorporation by 
Reference, Safety.

Adoption of the Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends 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 U.S.C. 106(g), 40113, 44701.


Sec. 39.13  [Amended]

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

2000-25-01  The New Piper Aircraft, Inc. (formerly Piper Aircraft 
Corporation): Amendment 39-12035; Docket No. 96-CE-69-AD; Supersedes 
AD 80-26-05, Amendment 39-3994.

    (a) What airplanes are affected by this AD? The following 
airplane models and serial numbers that are:
    (1) Certificated in any category; and
    (2) Equipped with Piper part number 46653-00 or 47529-32 main 
landing gear door hinge assemblies made of aluminum (or FAA-approved 
equivalent part numbers).

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                         Models                                                Serial Nos.
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PA-31..................................................  31-2 through 31-900 and 31-7300901 through 31-8312019.
PA-31-300..............................................  31-2 through 31-900 and 31-7300901 through 31-8312019.
PA-31-350..............................................  31-5001 through 31-5004 and 31-7305005 through 31-
                                                          8553002.
PA-31-325..............................................  31-7400990, 31-7512001 through 31-8312019.
PA-31P.................................................  31P-1 through 31P-109 and 31P-7300110 through 31P-
                                                          7730012.
PA-31T.................................................  31T-7400002 through 31T-8120104.
PA-31T1................................................  31T-7804001 through 31T-8104073; 31T-8104101; 31T-
                                                          8304001 through 31T-8304003; and 31T-1104004 through
                                                          31T-1104017.
PA-31T2................................................  31T-8166001 through 31T-8166076, and 31T-1166001
                                                          through 31T-1166008.
PA-31T3................................................  31T-8275001 through 31T-8475001, and 31T-5575001.
PA-31P-350.............................................  31P-8414001 through 31P-8414050.
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    Note 1: Aircraft referred to as Model PA-31-310 are actually 
Model PA-31 airplanes. Actions specified for PA-31 airplanes must 
also be performed. See also AD 80-26-05, Piper Service Bulletin No. 
682, dated July 24, 1980, and type certificate data sheet A20SO.

    (b) Who must comply with this AD? Anyone who wishes to operate 
any of the above airplanes must comply with this AD.
    (c) What problem does this AD address? The actions specified by 
this AD are intended to detect and correct cracked main landing gear 
(MLG) inboard door hinge assemblies. This could result in the MLG 
becoming jammed with consequent loss of control of the airplane 
during landing operations.

[[Page 78905]]

    (d) What actions must I accomplish to address this problem? To 
address this problem, you must accomplish the following:

------------------------------------------------------------------------
           Action                Compliance time         Procedures
------------------------------------------------------------------------
(1) For airplanes with any    Inspect upon          Accomplish in
 MLG inboard door hinge        accumulating 2,000    accordance with the
 assembly that is Piper part   hours time-in-        INSTRUCTIONS
 number 47529-32 (or FAA-      service (TIS) on      section of Piper
 approved equivalent part      the MLG inboard       Service Bulletin
 number), accomplish the       door hinge assembly   No. 682, dated July
 following:                    or within the next    24, 1980
(i) Inspect all hinges and     100 hours TIS after
 hinge attachment angles in    January 19, 2001
 the MLG inboard door hinge    (the effective date
 assembly; and.                of this AD),
                               whichever occurs
                               later; and
                               thereafter at
                               intervals not to
                               exceed 2,000 hours
                               TIS. Accomplish the
                               replacement, if
                               necessary, prior to
                               further flight
                               after the
                               inspection
    (ii) Replace any cracked
     MLG inboard door hinge
     assembly with a Piper
     part number 47529-32
     assembly (or FAA-
     approved equivalent
     part number)
(2) For airplanes with any    Inspect at the next   Accomplish in
 aluminum MLG inboard door     inspection required   accordance with the
 hinge assembly that is not    by AD 80-26-05 or     INSTRUCTIONS
 Piper part number 47529-32    within the next 100   section of Piper
 (or FAA-approved equivalent   hours time-in-        Service Bulletin
 part number) or any           service (TIS) after   No. 682, dated July
 assembly that is not made     January 19, 2001      24, 1980.
 of steel, accomplish the      (the effective date
 following:                    of this AD),
(i) Inspect all hinges and     whichever occurs
 hinge attachment angles in    first, and
 the MLG inboard door hinge    thereafter at
 assembly; and.                intervals not to
                               exceed 100 hours
                               TIS. Accomplish the
                               replacement, if
                               necessary, prior to
                               further flight
                               after the
                               inspection where
                               the cracked
                               assembly was found
    (ii) Replace any cracked
     MLG inboard door hinge
     assembly with a Piper
     part number 47529-32
     assembly (or FAA-
     approved equivalent
     part number)
------------------------------------------------------------------------

    (e) Can I comply with this AD in any other way?
    (1) You may use an alternative method of compliance or adjust 
the compliance time if:
    (i) Your alternative method of compliance provides an equivalent 
level of safety; and
    (ii) The Manager, Atlanta Aircraft Certification Office (ACO), 
approves your alternative. Submit your request through an FAA 
Principal Maintenance Inspector, who may add comments and then send 
it to the Manager, Atlanta ACO.
    (2) 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.

    Note 2: This AD applies to each airplane identified in paragraph 
(a) of this AD, 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 (e) 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 you have not eliminated the unsafe condition, specific 
actions you propose to address it.

    (f) Where can I get information about any already-approved 
alternative methods of compliance? Contact William O. Herderich, 
Aerospace Engineer, FAA, Atlanta Aircraft Certification Office, One 
Crown Center, 1895 Phoenix Boulevard, suite 450, Atlanta, Georgia 
30349; telephone: (770) 703-6082; facsimile: (770) 703-6097; e-mail: 
[email protected].
    (g) What if I need to fly the airplane to another location to 
comply with this AD? The FAA can issue a special flight permit under 
sections 21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR 21.197 and 21.199) to operate your airplane to a location where 
you can accomplish the requirements of this AD
    (h) Are any service bulletins incorporated into this AD by 
reference? Actions required by this AD must be done in accordance 
with Piper Service Bulletin No. 682, dated July 24, 1980. The 
Director of the Federal Register approved this incorporation by 
reference under 5 U.S.C. 552(a) and 1 CFR part 51. You can get 
copies from The New Piper Aircraft, Inc., Customer Service, 2926 
Piper Drive, Vero Beach, Florida 32960. You can look at copies at 
FAA, Central Region, Office of the Regional Counsel, 901 Locust, 
Room 506, Kansas City, Missouri, or at the Office of the Federal 
Register, 800 North Capitol Street, NW, suite 700, Washington, DC.
    (i) Does this AD action affect any existing AD actions? This 
amendment supersedes AD 80-26-05, Amendment 39-3994.
    (j) When does this amendment become effective? This amendment 
becomes effective on January 19, 2001.

    Issued in Kansas City, Missouri, on November 30, 2000.
William J. Timberlake,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 00-31451 Filed 12-15-00; 8:45 am]
BILLING CODE 4910-13-P