[Federal Register Volume 61, Number 166 (Monday, August 26, 1996)]
[Proposed Rules]
[Pages 43687-43689]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-21597]
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Proposed Rules
Federal Register
________________________________________________________________________
This section of the FEDERAL REGISTER contains notices to the public of
the proposed issuance of rules and regulations. The purpose of these
notices is to give interested persons an opportunity to participate in
the rule making prior to the adoption of the final rules.
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Federal Register / Vol. 61, No. 166 / Monday, August 26, 1996 /
Proposed Rules
[[Page 43687]]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 96-NM-47-AD]
RIN 2120-AA64
Airworthiness Directives; Airbus Model A320-111, -211, -212, and
-231 Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: This document proposes the adoption of a new airworthiness
directive (AD) that is applicable to certain Airbus Model A320-111, -
211, -212, and -231 series airplanes. This proposal would require
repetitive inspections to detect cracks of the rear bracket attached to
the outboard rib of the shroud boxes and the surfaces of the lugs
adjacent to the bushes, and replacement, if necessary. This proposal
also would require replacement of the outboard aft brackets of the
shroud boxes with modified brackets that have floating boxes, which
would terminate the repetitive inspections. This proposal is prompted
by a report that the lug of the rear outboard bracket failed due to
fatigue. The actions specified by the proposed AD are intended to
prevent fatigue-related cracking in the subject lug, and the consequent
failure of this lug; this condition could result in the loss of the
shroud box, and, consequently, lead to reduced controllability of the
airplane.
DATES: Comments must be received by October 4, 1996.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 96-NM-47-AD, 1601 Lind Avenue, SW., Renton,
Washington 98055-4056. Comments may be inspected at this location
between 9:00 a.m. and 3:00 p.m., Monday through Friday, except Federal
holidays.
The service information referenced in the proposed rule 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.
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:
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 shall 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 summarizing 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 Number 96-NM-47-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, Transport Airplane Directorate, ANM-103, Attention: Rules
Docket No. 96-NM-47-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
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 A320-111, -211, -
212, and -231 series airplanes. The DGAC advises that it has received a
report indicating that, during major fatigue testing on a Model A320
fatigue test wing, the lug of the rear outboard bracket failed at
85,714 simulated flights. This failure was caused by the movement
between the shroud box, overwing panel, and the torque box. Such
movement applied a longitudinal load to the outboard aft bracket, which
resulted in the failure of the lug. Fatigue-related cracking in the
subject lug could cause its failure. If the lug fails, the resultant
loss of the shroud box could result in reduced controllability of the
airplane.
Explanation of Relevant Service Information
Airbus has issued Service Bulletin A320-57-1034, Revision 2, dated
September 8, 1995. The service bulletin describes procedures for
repetitive visual inspections to detect cracks of the rear bracket
attached to the outboard rib of the shroud boxes and the surfaces of
the lugs adjacent to the bushes, and replacement of the bracket with a
modified bracket, if any crack is detected.
The DGAC classified this service bulletin as mandatory and issued
French airworthiness directive 95-100-068(B), dated May 24, 1995, in
order to assure the continued airworthiness of these airplanes in
France.
In addition, Airbus has issued Service Bulletin A320-57-1035,
Revision 4, dated February 22, 1994, which describes procedures for
replacement of the outboard aft brackets of the shroud boxes with
modified brackets that have floating boxes. The modified brackets will
eliminate the longitudinal loads being applied to the outboard aft
brackets. Accomplishment of this replacement would eliminate the need
for repetitive inspections.
FAA's Conclusions
This airplane model is manufactured in France and is type
certificated for operation in the United States under the
[[Page 43688]]
provisions of section 21.29 of the Federal Aviation Regulations (14 CFR
21.29) 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 type design
that are certificated for operation in the United States.
Explanation of Requirements of Proposed Rule
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, the proposed AD would require repetitive visual
inspections to detect cracks of the rear bracket attached to the
outboard rib of the shroud boxes and the surfaces of the lugs adjacent
to the bushes, and replacement, if necessary. The proposed AD also
would require replacement of the outboard aft brackets of the shroud
boxes with modified brackets with floating boxes, which would
constitute terminating action for the repetitive inspection
requirements. The actions would be required to be accomplished in
accordance with the service bulletins described previously.
Differences Between the Proposal and the Related French AD
This proposed rule would differ from the parallel French
airworthiness directive 95-100-068(B), in that it would mandate the
accomplishment of the terminating action for the repetitive
inspections. The French airworthiness directive provides that action as
optional.
Mandating the terminating action is based on the FAA's
determination that long term continued operational safety will be
better assured by design changes to remove the source of the problem,
rather than by repetitive inspections. Long term inspections may not be
providing the degree of safety assurance necessary for the transport
airplane fleet. This, coupled with a better understanding of the human
factors associated with numerous continual inspections, has led the FAA
to consider placing less emphasis on inspections and more emphasis on
design improvements. The proposed requirement to accomplish the
terminating action is in consonance with these considerations.
The proposed rule also would differ from the parallel French
airworthiness directive in that its applicability would include, in
addition to other airplanes, Model A320-212 series airplanes. Since
issuance of the French airworthiness directive, Airbus has issued
Revision 2 of Service Bulletin A320-57-1034 (described above), which
revises the effectivity listing of Revision 1 of that service bulletin
by including Model A320-212 series airplanes. (The French AD references
this service bulletin as the appropriate source of service information;
however, does not reference any particular revision level.) The FAA has
determined that Model A320-212 series airplanes are subject to the
addressed unsafe condition.
Cost Impact
The FAA estimates that 70 Airbus Model A320-111, -211, -212, and -
231 series airplanes of U.S. registry would be affected by this
proposed AD.
It would take approximately 1 work hour per airplane to accomplish
the proposed inspection, at an average labor rate of $60 per work hour.
Based on these figures, the cost impact of the inspection proposed by
this AD on U.S. operators is estimated to be $4,200, or $60 per
airplane, per inspection cycle.
It would take approximately 35 work hours per airplane to
accomplish the proposed modification, at an average labor rate of $60
per work hour. Required parts would cost approximately $2,170 per
airplane. Based on these figures, the cost impact of the modification
proposed by this AD on U.S. operators is estimated to be $298,900, or
$4,270 per airplane.
The cost impact figures discussed above are based on assumptions
that no operator has yet accomplished any of the proposed requirements
of this AD action, and that no operator would accomplish those actions
in the future if this AD were not adopted.
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 proposed
regulation (1) is not a ``significant regulatory action'' under
Executive Order 12866; (2) is not a ``significant rule'' under the 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 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, 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), 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
Airbus Industrie: Docket 96-NM-47-AD.
Applicability: Model A320-111, -211, -212, and -231 series
airplanes, as listed in Airbus Service Bulletin A320-57-1034,
Revision 2, dated September 8, 1995; 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 otherwise
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 (c) 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 fatigue-related cracking in the shroud box attachment
lug, which could result in the loss of the shroud box, and,
consequently, lead to reduced controllability of the airplane,
accomplish the following:
(a) Prior to the accumulation of 17,000 total landings, or
within 12 months after the effective date of this AD, whichever
occurs later, perform a detailed visual inspection to detect cracks
of the rear bracket attached to the outboard rib of the shroud boxes
and the surfaces of the lugs adjacent to the bushes, in accordance
with Airbus Service Bulletin
[[Page 43689]]
A320-57-1034, Revision 2, dated September, 8, 1995.
Note 2: Inspections accomplished prior to the effective date of
this amendment in accordance with Airbus Service Bulletin A320-57-
1034, Revision 1, dated August 24, 1992, are considered acceptable
for compliance with the requirements of paragraph (a) of this AD.
(1) If no crack is detected, repeat the visual inspection
thereafter at intervals specified in paragraph (a)(1)(i) or
(a)(1)(ii), as applicable.
(i) For Model A320-100 series airplanes: Repeat at intervals not
to exceed 6,000 landings.
(ii) For Model A320-200 series airplanes: Repeat at intervals
not to exceed 4,800 landings.
(2) If any crack is detected, prior to further flight, replace
the bracket with a modified bracket, in accordance with Airbus
Service Bulletin A320-57-1035, Revision 4, dated February 22, 1994.
Accomplishment of this replacement terminates the requirements of
this AD for that bracket.
(b) Within 4 years following accomplishment of paragraph (a) of
this AD, replace the outboard aft brackets of the shroud boxes with
modified brackets that have floating boxes, in accordance with
Airbus Service Bulletin A320-57-1035, Revision 4, dated February 22,
1994. Accomplishment of this replacement constitutes terminating
action for the repetitive inspections requirements of paragraph (a)
of this AD.
(c) 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 3: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Standardization Branch, ANM-113.
(d) 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.
Issued in Renton, Washington, on August 19, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 96-21597 Filed 8-23-96; 8:45 am]
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