[Federal Register Volume 62, Number 203 (Tuesday, October 21, 1997)]
[Proposed Rules]
[Pages 54595-54598]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-27794]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 96-CE-69-AD]
RIN 2120-AA64
Airworthiness Directives; The New Piper Aircraft, Inc. (Formerly
Piper Aircraft Corporation), Models PA-31, PA-31-300, PA-31-325, PA-31-
350, PA-31P, PA-31T, and PA-31T1 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 certain The
New Piper Aircraft, Inc. (Piper) Models PA-31, PA-31-300, PA-31-325,
PA-31-350, PA-31P, PA-31T, and PA-31T1 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 proposed 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 (or approved hinges and angles made of
steel), when incorporated, will eliminate the need for the currently
required repetitive short-interval inspections. The proposed AD would
retain the current repetitive inspections contained in AD 80-26-05, and
would require installing these improved design or approved steel parts
as terminating action for the repetitive inspection requirement. The
actions specified in the proposed AD are intended to prevent separation
of the MLG inboard door from the airplane caused by a cracked inboard
door hinge or attachment angle, which could result in the MLG becoming
jammed with consequent loss of control of the airplane during landing
operations.
DATES: Comments must be received on or before December 26, 1997.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Central Region, Office of the Regional Counsel,
Attention: Rules Docket No. 96-CE-69-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, One Crown Center, 1895
Phoenix Boulevard, suite 450, Atlanta, Georgia 30349; telephone (770)
703-6079; facsimile (770) 703-6097.
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. 96-CE-69-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 Regional Counsel, Attention:
Rules Docket No. 96-CE-69-AD, Room 1558, 601 E. 12th Street, Kansas
City, Missouri 64106.
Discussion
On December 1, 1995, the FAA issued a proposal to amend part 39 of
the Federal Aviation Regulations (14 CFR part 39) to include an AD that
would apply to Piper Models PA-31, PA-31-325, PA-31-350, PA-31P, PA-
31T, and PA-31T1 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 (1) retain the requirement of 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; and (2) require incorporating a MLG
inboard
[[Page 54596]]
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 have been in
accordance with Piper Service Bulletin (SB) No. 682, dated July 24,
1980.
Interested persons have been afforded an opportunity to participate
in the making of this amendment. Due consideration was given to the one
comment received.
Explanation of the Comment Received on the NPRM
The comment received on the NPRM contained information that the
improved design hinge assemblies, part number (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 states that its airplane fleet
has experienced three failures and three incidents related to fatigue
cracking of the P/N 47529-32 hinge assemblies.
Subsequent Actions
The FAA conducted a review of the manufacturer's service history
and service difficulty reports in the FAA 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, the
FAA determined that more information and analysis were needed before
MLG inboard door hinge assembly replacements were mandated through an
AD, as terminating action for the repetitive inspections currently
required by AD 80-26-05.
With the above information in mind, the FAA issued, on February 11,
1997, an advance notice of proposed rulemaking (ANPRM) to provide an
opportunity for the general public to participate in the decision as to
what course of rulemaking the FAA should take. The ANPRM was published
in the Federal Register on February 19, 1997 (62 FR 7375). At this
time, the FAA also withdrew the NPRM.
Interested persons were encouraged to provide information that
describes what they consider the best action (if any) to be taken
regarding the P/N 47529-32 MLG hinge assembly. No information or
comments were received on the ANPRM.
The FAA's Analysis and Determination
The FAA service difficulty database contains 10 reports of failure
or cracks found in the MLG inboard door hinge assembly on the affected
airplanes. Six of these reports were submitted by the commenter to the
NPRM, with three of these incidents attributed to the original MLG
inboard door hinge assemblies. The other four reports are not clear as
to whether the original MLG inboard door hinge assemblies were
installed or the improved design assemblies were installed. However,
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, the FAA presumes that the original hinge
assemblies were installed.
The FAA has reviewed the three incident reports on the improved
design MLG inboard door hinge assemblies and performed extensive
testing and analysis of the improved design MLG inboard door hinge
assemblies. The FAA has determined that the incidents were isolated and
that mandating repetitive inspections is not needed when the P/N 47529-
32 MLG inboard door hinge assemblies are installed. The FAA has
determined that Piper Model PA-31-300 airplanes incorporate the same
type design as the other PA-31 series airplanes and could incorporate
the same part number MLG inboard door hinge assemblies.
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 (1) eliminate the repetitive short-
interval inspections required by AD 80-26-05; and (2) prevent
separation of a MLG door from the airplane caused by a cracked inboard
door hinge or attachment angle, which could result in the MLG becoming
jammed with consequent loss of control of the airplane during landing
operations.
Explanation of the Provisions of the Proposed AD
Since an unsafe condition has been identified that is likely to
exist or develop in other Piper Models PA-31, PA-31-300, PA-31-325, PA-
31-350, PA-31P, PA-31T, and PA-31T1 airplanes of the same type design,
the FAA is proposing an AD. 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's Aging Commuter-Class Aircraft Policy
The actions proposed in this AD are part of the 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 the 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. In determining what inspections are critical, the
FAA considers (1) the safety consequences of the airplane if the known
problem is not detected by the inspection; (2) the reliability of the
inspection such as the probability of not detecting the known problem;
(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.
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.
Cost Impact
The FAA estimates that 1,769 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 $2,000 per airplane ($500 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 $3,750,280 or $2,120
per airplane. This figure is based on the presumption 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
[[Page 54597]]
separate assemblies) of the affected airplanes. Presuming 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 $848,000 from
$3,750,280 to $2,902,280.
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 1,369 affected
airplanes (1,769 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.
Compliance Time of the Proposed AD
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 PA-
31, PA-31-300, PA-31-325, PA-31-350, PA-31P, PA-31T, and PA-31T1
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 and
general aviation, while still minimizing the impact on the private
airplane owners of Piper Models PA-31, PA-31-300, PA-31-325, PA-31-350,
PA-31P, PA-31T, and PA-31T1 airplanes.
Regulatory Impact
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 U.S.C. 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. 96-CE-69-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 main landing gear (MLG) inboard door hinge
assemblies or FAA-approved MLG inboard door hinges and attachment
angles made of steel at all four hinge assembly locations:
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Models Serial numbers
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PA-31, PA-31-300, and PA-31-325....... 31-2 through 31-8012077.
PA-31-350............................. 31-5001 through 31-8052168.
PA-31P................................ 31P-3 through 31P-7730012.
PA-31T................................ 31T-7400002 through 31T-8020076.
PA-31T1............................... 31T-7804001 through 31T-8004040.
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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 MLG door from the airplane caused by
a cracked MLG inboard door hinge or attachment angle, which could
result in the MLG becoming jammed with consequent 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
[[Page 54598]]
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, install a
Piper P/N 47529-32 MLG inboard door hinge and attachment angle
assembly or install FAA-approved MLG inboard door 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, install a Piper P/N 47529-32 MLG inboard door hinge and
attachment angle assembly in all four hinge assembly locations or
install FAA-approved MLG inboard door hinges and angles made of
steel in all four hinge assembly locations.
(e) Installing a Piper P/N 47529-32 MLG inboard door hinge and
attachment angle assembly in all four assembly locations or
installing FAA-approved MLG inboard door 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), One Crown Center, 1895 Phoenix Boulevard, suite 450, Atlanta,
Georgia 30349.
(1) The request shall be forwarded through an appropriate FAA
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: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Atlanta ACO.
(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
Regional Counsel, Room 1558, 601 E. 12th Street, Kansas City,
Missouri 64106.
(i) This amendment supersedes AD 80-26-05, mendment 39-3994.
Issued in Kansas City, Missouri, on October 14, 1997.
Mary Ellen Schutt,
Acting Manager, Small Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 97-27794 Filed 10-20-97; 8:45 am]
BILLING CODE 4910-13-U