[Federal Register Volume 61, Number 37 (Friday, February 23, 1996)]
[Rules and Regulations]
[Pages 6924-6927]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-3149]
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[[Page 6925]]
DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 95-NM-262-AD; Amendment 39-9515; AD 96-04-04]
Airworthiness Directives; Airbus Model A340 Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule; request for comments.
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SUMMARY: This amendment adopts a new airworthiness directive (AD),
applicable to certain Airbus Model A340 series airplanes. This action
requires repetitive inspections to detect corrosion and cracking of the
shortening mechanism pins in the main landing gear (MLG), and repair or
replacement, if necessary. It also requires replacement of the
shortening mechanism pin and retraction mechanism pins; the forward
pintle pin; the shortening mechanism bellcrank pin; and the bellcrank
subassembly of the shortening mechanism. This amendment is prompted by
reports of failure of the shortening mechanism pins due to improper
grinding of the chrome plating during manufacture, which led to the
initiation of stress corrosion and cracks. The actions specified in
this AD are intended to prevent failure of these pins, which could lead
to a significant reduction of the shock absorber capability or damage
to various components of the MLG, and eventually could lead to the
failure of the MLG.
DATES: Effective March 11, 1996.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of March 11, 1996.
Comments for inclusion in the Rules Docket must be received on or
before April 23, 1996.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 95-NM-262-AD, 1601 Lind Avenue, SW.,
Renton, Washington 98055-4056.
The service information referenced in this AD may be obtained from
Airbus Industrie, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex,
France. This information may be examined at the FAA, Transport Airplane
Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the
Office of the Federal Register, 800 North Capitol Street NW., suite
700, Washington, DC.
FOR FURTHER INFORMATION CONTACT: Charles Huber, Aerospace Engineer,
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate,
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206)
227-2589; fax (206) 227-1149.
SUPPLEMENTARY INFORMATION: The Direction Generale de l'Aviation Civile
(DGAC), which is the airworthiness authority for France, recently
notified the FAA that an unsafe condition may exist on certain Airbus
Model A340 series airplanes. The DGAC advises that there have been two
cases of failure of the shortening mechanism pin of the main landing
gear (MLG) assembly on in-service airplanes.
In one case, investigation revealed that the pin had broken into
three parts, the chrome plating was detached from the base metal around
the breaks, and heavy corrosion was present on all of the fracture
surfaces. A metallurgical analysis of the broken pin concluded that the
pin fractures were the result of cracks in the pin's chrome plating and
subsequent stress corrosion. The cracks in the chrome plating most
likely occurred as a result of ``grinding abuse'' when the pin was
ground during manufacture. The subsequent penetration of moisture
through the cracks to the base metal initiated the stress corrosion and
the local detachment of the chrome plating.
In the second case, investigation revealed that the pin had failed
as a result of damage caused by stress corrosion.
The DGAC also advises that similar ``grinding abuse'' may also be
present on some forward pintle pins installed on the main strut and
dressings of certain affected airplanes, and on the shortening
mechanism bellcrank pins of the bellcrank subassembly of the MLG.
Failure of the shortening mechanism pin on the MLG could result in
substantial damage to the shortening mechanism, the shock absorber, and
the inner top side of the main fitting. This condition could lead to a
significant reduction of the shock absorber capability, and eventually
could lead to the failure of the MLG.
Likewise, failure of the forward pintle pins or the shortening
mechanism bellcrank pins could also result in damage to the shortening
mechanism and/or the surrounding area and components, and eventually
could lead to the failure of the MLG.
Airbus Industrie has issued the following service bulletins that
contain procedures to address this problem:
1. Airbus Service Bulletin A340-32-4050, dated April 10, 1995; and
Revision 1, dated May 17, 1995. These service bulletins describe
procedures for conducting repetitive visual inspections to detect
cracks and corrosion of the shortening mechanism pins. The inspection
procedures also call for a one-time lubricating of the affected
shortening mechanism links. The service bulletins also describe
procedures for replacement of the shortening mechanism pin and
retraction mechanism pins of the MLG (left- and right-hand side) with
pins that are properly chrome-plated and not susceptible to problems
associated with corrosion. (These service bulletins refer to Messier-
Dowty Service Bulletins A33/34-32-29 and A33/34-32-30 for more detailed
procedural instructions.)
2. Airbus Service Bulletin A340-32-4058, dated April 10, 1995; and
Revision 1, dated May 17, 1995. These service bulletins describe
procedures for removing discrepant forward pintle pins and replacing
them with new or reworked pintle pins that are not susceptible to the
problems associated with corrosion. This replacement will ensure the
integrity of the affected components of the MLG. (These service
bulletins refer to Messier-Dowty Service Bulletins A33/34-32-28 and
A33/34-32-32 for more detailed procedural instructions.)
3. Airbus Service Bulletin A340-32-4062, dated May 17, 1995. This
service bulletin describes procedures for replacing discrepant
shortening mechanism bellcrank pins with new or serviceable pins that
are not susceptible to the problems associated with corrosion. It also
describes procedures for replacing the bellcrank subassembly of the
shortening mechanism of the MLG. These replacements will ensure the
integrity of the affected components of the bellcrank and the MLG.
(This service bulletin refers to Messier-Dowty Service Bulletins A33-
34-32-44 and A33/34-32-45 for more detailed procedural instructions.
The DGAC classified these service bulletins as mandatory and issued
French airworthiness directive (CN) 94-244-012(B)R3, dated July 19,
1995, in order to assure the continued airworthiness of these airplanes
in France.
This airplane model is manufactured in France and is type
certificated for operation in the United States under the provisions of
section 21.29 of the Federal Aviation Regulations (14 CFR 21.19) and
the applicable bilateral airworthiness agreement. Pursuant to this
bilateral airworthiness agreement, the DGAC has kept the FAA informed
of the situation described above. The FAA has examined the findings of
the DGAC, reviewed all available information, and determined that AD
action is necessary for products of this
[[Page 6926]]
type design that are certificated for operation in the United States.
Since an unsafe condition has been identified that is likely to
exist or develop on other airplanes of the same type design registered
in the United States, this AD is being issued to prevent failure of the
MLG. This AD requires, initially, repetitive visual inspections to
detect damage or cracks of the shortening mechanism pivot pin, and
replacement, if necessary. It also requires a one-time lubrication
(greasing) of the MLG shortening mechanism main links.
This AD also requires replacement of the following items:
1. The shortening mechanism pivot pin, and the retraction mechanism
pins of the MLG on the left- and right-hand sides (after these
replacements are accomplished, the required repetitive visual
inspections are terminated);
2. The forward pintle pin fitted to the MLG;
3. The shortening mechanism bellcrank pin of the MLG; and
4. The bellcrank subassembly of the shortening mechanism of the
MLG.
These actions are required to be accomplished in accordance with
the service bulletins described previously.
None of the Model A340 series airplanes affected by this action are
on the U.S. Register. All airplanes included in the applicability of
this rule currently are operated by non-U.S. operators under foreign
registry; therefore, they are not directly affected by this AD action.
However, the FAA considers that this rule is necessary to ensure that
the unsafe condition is addressed in the event that any of these
subject airplanes are imported and placed on the U.S. Register in the
future.
Should an affected airplane be imported and placed on the U.S.
Register in the future, the following costs could be expected:
Inspection of the shortening mechanism pivot pin would require
approximately .5 work hour to accomplish the required actions, at an
average labor charge of $60 per work hour. Based on these figures, the
cost impact of this inspection requirement would be $30 per airplane
per inspection cycle.
Replacement of the shortening mechanism pivot pin and retraction
mechanism pins would require approximately 118 work hours per airplane
to accomplish, at an average labor charge of $60 per work hour. Based
on these figures, the cost impact of this replacement requirement would
be $7,080 per airplane.
Replacement of the forward pintle pin would require approximately
92 work hours per airplane to accomplish, at an average labor charge of
$60 per work hour. Based on these figures, the cost impact of this
replacement requirement would be $5,520 per airplane.
Replacement of the shortening mechanism bellcrank pin and bellcrank
subassembly would require approximately 13 work hours per airplane to
accomplish, at an average labor charge of $60 per work hour. Based on
these figures, the cost impact of this replacement requirement would be
$780 per airplane.
Since this AD action does not affect any airplane that is currently
on the U.S. register, it has no adverse economic impact and imposes no
additional burden on any person. Therefore, notice and public
procedures hereon are unnecessary and the amendment may be made
effective in less than 30 days after publication in the Federal
Register.
Comments Invited
Although this action is in the form of a final rule and was not
preceded by notice and opportunity for public comment, comments are
invited on this rule. Interested persons are invited to comment on this
rule by submitting such written data, views, or arguments as they may
desire. Communications shall identify the Rules Docket number and be
submitted in triplicate to the address specified under the caption
ADDRESSES.
All communications received on or before the closing date for
comments will be considered, and this rule may be amended in light of
the comments received. Factual information that supports the
commenter's ideas and suggestions is extremely helpful in evaluating
the effectiveness of the AD action and determining whether additional
rulemaking action would be needed.
Comments are specifically invited on the overall regulatory,
economic, environmental, and energy aspects of the rule that might
suggest a need to modify the 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
AD will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments
submitted in response to this rule must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket Number 95-NM-262-AD.'' The postcard will be date stamped and
returned to the commenter.
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 final evaluation has been prepared for this action
and it is contained in the Rules Docket. A copy of it may be obtained
from 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. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
96-04-04 Airbus: Amendment 39-9515. Docket 95-NM-262-AD.
Applicability: Model A340 series airplanes; having
manufacturer's serial numbers (MSN) 002 through 009 inclusive, 011,
013 through 016 inclusive, 018 through 029 inclusive, 031 through
036 inclusive, or 038; certificated in any category.
Note 1: This AD applies to each airplane identified in the
preceding applicability provision, regardless of whether it has been
otherwise 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
[[Page 6927]]
owner/operator must request approval for an alternative method of
compliance in accordance with paragraph (d) 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, unless accomplished
previously.
To prevent collapse of the main landing gear, accomplish the
following:
(a) For airplanes having MSN 005 through 009 inclusive, 011, 013
through 016 inclusive, 018 through 029 inclusive, 031 through 034
inclusive, or 038: Accomplish the requirements of paragraphs (a)(1)
and (a)(2) of this AD:
(1) Within 7 days after the effective date of this AD, perform a
visual inspection to detect corrosion and cracks of the shortening
mechanism (pivot) pins of the main landing gear (MLG), in accordance
with Airbus Service Bulletin A340-32-4050, dated April 10, 1995, or
Revision 1, dated May 17, 1995.
(i) If no corrosion or cracking is found, repeat the inspection
thereafter at intervals not to exceed 7 days.
(ii) If any corrosion or cracking is found, prior to further
flight, replace the shortening mechanism pin and the retraction
mechanism pin with a new pin in accordance with the service
bulletin. Accomplishment of this replacement constitutes terminating
action for the repetitive inspections required by paragraph
(a)(1)(i) of this AD.
(2) Within 7 days after the effective date of this AD, perform a
one-time lubrication (greasing) of the MLG shortening mechanism main
links in accordance with the service bulletin.
(b) Prior to the accumulation of 1,500 total landings, or within
3 months after the effective date of this AD, whichever occurs
later, but no later than 12 months after the effective date of this
AD, accomplish the requirements of paragraphs (b)(1), (b)(2), and
(b)(3) of this AD, as applicable.
(1) For airplanes having MSN 005 through 009 inclusive, 011, 013
through 016 inclusive, 018 through 029 inclusive, 031 through 034
inclusive, or 038: Replace the shortening mechanism pivot pin, and
the retraction mechanism pins of the MLG, left- and right-hand side,
in accordance with Airbus Service Bulletin A340-32-4050, dated April
10, 1995, or Revision 1, dated May 17, 1995.
(2) For airplanes having MSN 021 through 029 inclusive, or 031
through 034 inclusive: Replace the forward pintle pins fitted to the
MLG in accordance with Airbus Service Bulletin A340-32-4058, dated
April 10, 1995, or Revision 1, dated May 17, 1995.
(3) For airplanes having MSN 002 through 009 inclusive, 011, 013
through 016 inclusive, 018 through 029 inclusive, or 031 through 036
inclusive: Replace the shortening mechanism bellcrank pin of the MLG
in accordance with Airbus Service Bulletin A340-32-4062, dated May
17, 1995.
(c) For airplanes having MSN 002 through 009 inclusive, 011, 013
through 016 inclusive, 018 through 029 inclusive, or 031 through 036
inclusive: Prior to the accumulation of 7,250 total landings, or
within 3 months after the effective date of this AD, whichever
occurs later, replace the bellcrank subassembly of the shortening
mechanism of the MLG in accordance with Airbus Service Bulletin
A340-32-4062, dated May 17, 1995.
(d) An alternative method of compliance or adjustment of the
compliance time that provides an acceptable level of safety may be
used if approved by the Manager, Standardization Branch, ANM-113,
FAA, Transport Airplane Directorate. Operators shall submit their
requests through an appropriate FAA Principal Maintenance Inspector,
who may add comments and then send it to the Manager,
Standardization Branch, ANM-113.
Note 2: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Standardization Branch, ANM-113.
(e) 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.
(f) The actions shall be done in accordance with the following
Airbus service bulletins, which contain the following list of
effective pages:
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Airbus service bulletin and date Page No. Revision level shown on page Date shown on page
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A340-32-4050, April 10, 1995..................... 1-15- (Original)- April 10, 1995.
A340-32-4050, Revision 1, May 17, 1995-.......... 1, 2, 5, 10- 1- May 17, 1995.
3, 4, 6-9, 11-15- (Original)- April 10, 1995.
A340-32-4058, April 10, 1995..................... 1-10- (Original)- April 10, 1995.
A340-32-4058, Revision 1, May 17, 1995-.......... 1-3, 7-9- 1- May 17, 1995.
4-6, 10- (Original)- April 10, 1995.
A340-32-4062, May 17, 1995....................... 1-10- (Original)- May 17, 1995.
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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 Airbus Industrie, 1 Rond Point
Maurice Bellonte, 31707 Blagnac Cedex, France. Copies may be
inspected at the FAA, Transport Airplane Directorate, 1601 Lind
Avenue, SW., Renton, Washington; or at the Office of the Federal
Register, 800 North Capitol Street NW., suite 700, Washington, DC.
(g) This amendment becomes effective on March 11, 1996.
Issued in Renton, Washington, on February 7, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 96-3149 Filed 2-22-96; 8:45 am]
BILLING CODE 4910-13-P
