[Federal Register Volume 59, Number 122 (Monday, June 27, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-15379]
[[Page Unknown]]
[Federal Register: June 27, 1994]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 93-CE-58-AD; Amendment 39-8952; AD 94-13-11]
Airworthiness Directives: Piper Aircraft Corporation Models PA34-
200, PA34-200T, PA34-220T, PA44-180, and PA44-180T Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule.
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SUMMARY: This amendment adopts a new airworthiness directive (AD) that
applies to certain Piper Aircraft Corporation (Piper) Models PA34-200,
PA34-200T, PA34-220T, PA44-180, and PA44-180T airplanes. This action
requires repetitively inspecting the main landing gear trunnions for
cracks, replacing any trunnions found cracked, and eventually replacing
these trunnions with improved parts as terminating action for the
repetitive inspection requirement. Several reports of the main landing
gear trunnions cracking on the affected airplanes prompted this action.
The actions specified by this AD are intended to prevent collapse of
the main landing gear caused by cracked trunnions, which could result
in airplane damage.
DATES: Effective August 12, 1994.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of August 12, 1994.
ADDRESSES: Service information that applies to this AD may be obtained
from the Piper Aircraft Corporation, Customer Services, 2926 Piper
Drive, Vero Beach, Florida 32960. This information may also be examined
at the Federal Aviation Administration (FAA), Central Region, Office of
the Assistant Chief Counsel, Room 1558, 601 E. 12th Street, 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: Christina Marsh, Aerospace Engineer,
FAA, Atlanta Aircraft Certification Office, 1669 Phoenix Parkway, Suite
210C, Atlanta, Georgia 30349; telephone (404) 991-2910; facsimile (404)
991-3606.
SUPPLEMENTARY INFORMATION: 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 Models PA34-200, PA34-200T, PA34-220T, PA44-180, and
PA44-180T airplanes was published in the Federal Register on January
12, 1994 (59 FR 1676). The action proposed to require repetitively
inspecting the MLG trunnions for cracks, replacing any trunnions found
cracked, and eventually replacing these trunnions with improved parts
as terminating action for the repetitive inspection requirement. The
proposed inspections would be accomplished in accordance with Piper
Service Bulletin (SB) No. 787B, dated August 25, 1993. The proposed
replacement would be accomplished in accordance with the applicable
maintenance manual.
Interested persons have been afforded an opportunity to participate
in the making of this amendment. Due consideration has been given to
the four comments received.
One commenter states that, with the way the compliance of paragraph
(b) of the proposal is currently written, airplanes with trunnions that
have over 2,000 hours time-in-service (TIS) are grounded. The commenter
requests that the FAA give airplane operators in this scenario a grace
period. The FAA concurs and has changed the compliance portion of
paragraph (b) of the AD to: ``Upon the accumulation of 2,000 hours TIS
on a MLG trunnion or within the next 100 hours TIS, whichever occurs
later, * * *''. This change would give 100 hours TIS for compliance to
those operators with 1,901 hours TIS or more accumulated on a trunnion
as of the effective date of the AD.
This same commenter also states that, in paragraph (b)(1) of the
proposal, an affected airplane could be grounded if parts were not
available after 2,500 hours TIS (2,000 hours TIS replacement compliance
and 500 hours TIS for parts unavailability grace period). This
commenter recommends that, if parts are unavailable, the FAA allow the
owner/operator to inspect the airplane every 100 hours TIS until parts
are available and not just for the next 500 hours TIS. The FAA concurs
that airplanes would be grounded at 2,500 hours TIS if parts were not
available. However, the Piper Aircraft Corporation has assured the FAA
that an adequate surplus of parts currently exist for all operators to
comply with this action. The AD is unchanged as a result of this
comment.
One commenter recommends that, instead of mandatory replacement,
the FAA mandate the 100-hour TIS repetitive inspections with mandatory
replacement of trunnions found cracked. The FAA does not concur. The
FAA analyzed information related to MLG trunnion failures from service
difficulty reports and manufacturer's warranty claims; and, from this
information, the FAA established the mandatory replacement in order to
maintain these airplanes at their original type certification level of
safety. The AD is unchanged as a result of this comment.
Another commenter feels that an eddy current inspection of the MLG
trunnions is more reliable than the dye penetrant inspections. This
commenter states that, based upon similar MLG trunnion failures in the
United Kingdom, the dye penetrant inspection method may not detect a
critical crack. The FAA does not concur. Past experience based on FAA
reports indicates that dye penetrant inspections are very successful in
detecting cracks in the MLG trunnions, and the equipment needed is more
readily available and less costly than that for eddy current
inspections. The FAA will consider any requests to accomplish an eddy
current inspections as an alternative method of compliance to paragraph
(a) of the AD under provisions specified in paragraph (d) of the AD.
The AD is unchanged as a result of this comment.
This same commenter addresses lateral grinding marks found on a
significant number of MLG trunnions in the area of the past crack
initiation. This commenter recommends blending these marks out to
remove any traces of scoring. The FAA concurs, and has added provisions
for this requirement to the AD.
A commenter recommends that this AD action also cover inspections
in two other locations in the MLG, the swivel pin and trunnion attach
fittings. The FAA issued an advanced notice of proposed rulemaking
(ANPRM) on February 11, 1994, to seek comments regarding the best
action (if any) to take in order to correct any possible problems with
retractable MLG swivel pins. The FAA is currently reviewing comments
from this ANPRM and has not determined that there is an unsafe
condition that requires AD action under part 39 of the Federal Aviation
Regulations (14 CFR part 39). The MLG trunnion attach fittings are the
subject of Piper SB No. 956, dated March 3, 1992. The FAA has evaluated
all information related to this issue and has determined that AD action
is not justified at this point. The FAA will continue to evaluate any
additional information, and, if necessary, will implement future
rulemaking. The AD is unchanged as a result of this comment.
The manufacturer has informed the FAA that certain Piper Model
PA34-220T airplanes (serial numbers 34-8133001 through 34-8233088) may
be equipped with trunnion housing assemblies, Piper part number 39486-
802 (left) and 39486-803 (right) with embossed forging number 67924-2.
The FAA has determined that this AD should not apply to airplanes with
these trunnion housing assemblies installed. The FAA has revised the
Applicability section of the final rule to reflect this change.
No comments were received on the FAA's determination of the cost
impact of this proposed action upon U.S. operators of the affected
airplanes.
After careful review of all available information, the FAA has
determined that air safety and the public interest require the adoption
of the rule as proposed except for the compliance time change in
paragraph (b) of the proposal, the Applicability section change, the
addition of the provision to blend any lateral grinding marks, and
minor editorial corrections. The FAA has determined that these changes,
the addition, and any editorial corrections will not change the meaning
of the AD nor add any additional burden upon the public than was
already proposed.
The FAA estimates that 2,265 airplanes in the U.S. registry will be
affected by this AD, that it will take approximately 16 workhours per
airplane to accomplish the required action, and that the average labor
rate is approximately $55 an hour. Parts cost approximately $1,100 per
airplane. Based on these figures, the total cost impact of the AD on
U.S. operators is estimated to be $4,484,700. This figure is based on
the assumption that no affected airplane owner/operator has
accomplished the required action. The FAA believes that some airplane
owners have already accomplished the required actions. With this in
mind, the FAA anticipates that the cost of this AD will be much lower
than the figure referenced above.
The regulations adopted herein will 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 final
rule does 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) 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, pursuant to 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. App. 1354(a), 1421 and 1423; 49 U.S.C.
106(g); and 14 CFR 11.89.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding a new AD to read as follows:
94-13-11 Piper Aircraft Corporation: Amendment 39-8952; Docket No.
93-CE-58-AD.
Applicability: The following model and serial number airplanes
that are not equipped with main landing gear (MLG) trunnions (both
left and right side) that have either part number (P/N) 67926-30,
67926-31, 67926-32, 67926-33, 39486-14, or 39486-15, as applicable,
certificated in any category:
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Models Serial Nos.
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PA34-200........ 34-7250001 through 34-7450220.
PA34-200T....... 34-7570001 through 34-8170092.
PA34-220T....... 34-8133001 through 34-8233088 that are not equipped
with trunnion housing assemblies, Piper part number
39486-802 (left) and 39486-803 (right) with embossed
forging number 67924-2.
PA44-180........ 44-7995001 through 44-8195026, and 4495001 through
4495013.
PA44-180T....... 44-8107001 through 44-8207020.
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Compliance: Required as indicated, unless already accomplished.
To prevent collapse of the main landing gear caused by cracked
trunnions, which could result in airplane damage, accomplish the
following:
Note 1: The paragraph structure of this AD is as follows:
Level 1: (a), (b), (c), etc.
Level 2: (1), (2), (3), etc.
Level 3: (i), (ii), (iii), etc.
Level 2 and Level 3 structures are designations of the Level 1
paragraph they immediately follow.
(a) Upon the accumulation of 500 hours time-in-service (TIS) on
a MLG trunnion, dye-penetrant inspect the MLG trunnion for cracks in
accordance with the INSTRUCTIONS section of Piper Service Bulletin
(SB) No. 787B, dated August 25, 1993.
Note 2: If hours TIS on the MLG trunnion are unknown, hours TIS
accumulated on the airplane may be substituted.
(1) Prior to further flight, blend out any grinding marks in the
web area (depicted in the sketches of the SB referenced above),
using aluminum oxide paper, 300 grit (or finer), or an equivalent
material. Alodine and repaint areas where grinding marks are blended
out.
(2) For MLG trunnions found cracked, prior to further flight,
replace the cracked MLG trunnion with a part of improved design, P/N
67926-30, 67926-31, 67926-32, 67926-33, 39486-14, or 39486-15, as
applicable, in accordance with the applicable maintenance manual.
(3) For MLG trunnions not found cracked, reinspect at intervals
not to exceed 100 hours TIS until the replacement specified in
paragraph (b) of this AD is accomplished.
(4) If one trunnion is found cracked and is replaced as
specified in paragraph (a)(2) of this AD, the other trunnion must
still be reinspected as specified in paragraph (a)(3) of this AD
until it also is replaced.
(b) Upon the accumulation of 2,000 hours TIS on a MLG trunnion
or within the next 100 hours TIS after the effective date of this
AD, whichever occurs later, unless already accomplished as specified
in paragraph (a)(2) of this AD, replace each MLG trunnion with a
part of improved design, P/N 67926-30, 67926-31, 67926-32, 67926-33,
39486-14, or 39486-15, as applicable, in accordance with the
applicable maintenance manual.
(1) If parts for any MLG replacement have been ordered from the
manufacturer but are not available, prior to further flight and
thereafter at intervals not to exceed 100 hour TIS, dye-penetrant
inspect the MLG trunnion for cracks in accordance with the
INSTRUCTIONS section of Piper No. SB 787B, dated August 25, 1993. If
any one of the following occurs, prior to further flight, terminate
the above repetitive inspections and replace the trunnion as
specified in paragraph (b) of this AD:
(i) Parts become available;
(ii) A trunnion is found cracked; or
(iii) 2,500 hours TIS are accumulated on the trunnion or 500
hours TIS after the effective date of this AD, whichever occurs
later.
(2) Replacing both the left and right MLG trunnion with P/N
67926-30, 67926-31, 67926-32, 67926-33, 39486-14, or 39486-15, as
applicable, eliminates the inspection requirement of this AD.
(c) 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.
(d) 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), 1669 Phoenix Parkway, Suite 210C, Atlanta, Georgia 30349. 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 3: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Atlanta ACO.
(e) The inspections required by this AD shall be done in
accordance with Piper Service Bulletin No. 787B, dated August 25,
1993. This incorporation by reference was approved by the Director
of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR
part 51. Copies may be obtained from the Piper Aircraft Corporation,
2926 Piper Drive, Vero Beach, Florida 32960. Copies may be inspected
at the FAA, Central Region, Office of the Assistant Chief Counsel,
Room 1558, 601 E. 12th Street, Kansas City, Missouri, or at the
Office of the Federal Register, 800 North Capitol Street, NW., suite
700, Washington, DC.
(f) This amendment (39-8952) becomes effective on August 12,
1994.
Issued in Kansas City, Missouri, on June 17, 1994.
Barry D. Clements,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 94-15379 Filed 6-24-94; 8:45 am]
BILLING CODE 4910-13-U
