[Federal Register Volume 61, Number 90 (Wednesday, May 8, 1996)]
[Proposed Rules]
[Pages 20762-20764]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-11441]



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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration

14 CFR Part 39

[Docket No. 95-NM-241-AD]
RIN 2120-AA64


Airworthiness Directives; Airbus Model A310 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 A310 series 
airplanes. This proposal would require repetitive inspections to detect 
discrepancies of the slat universal joint and steady bearing 
assemblies, and replacement of any discrepant assembly with a new, like 
assembly. The proposal also would require replacement of all slat 
universal joint and steady bearing assemblies with improved assemblies, 
which would terminate the repetitive inspections. This proposal is 
prompted by reports of broken or missing inner races on the slat 
universal joint and steady bearing assemblies of the slat transmission 
system. The actions specified by the proposed AD are intended to 
prevent cracking of the inner race, which could cause it to break off 
and, consequently, allow the slat universal joint and steady bearing 
assemblies to become worn; this situation could result in failure of 
the shaft of the slat transmission system, and subsequent uncommanded 
movement of the associated slat.

DATES: Comments must be received by June 17, 1996.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 95-NM-241-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,

[[Page 20763]]

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 95-NM-241-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. 95-NM-241-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 A310 series 
airplanes. The DGAC advises that it has received reports that, during 
maintenance inspections, the inner races were found to be broken or 
missing on the slat universal joint and steady bearing assemblies of 
the slat transmission system. The existing design can cause these inner 
races to be susceptible to cracking. If the inner race cracks, it could 
break off, and the slat universal joint and steady bearing assemblies 
consequently could become worn. This condition, if not corrected, could 
result in failure of the shaft of the slat transmission system, and 
subsequent uncommanded movement of the associated slat.

Explanation of Relevant Service Information

    Airbus has issued Service Bulletin A310-27-2040, Revision 2, dated 
January 5, 1995. The service bulletin describes procedures for 
repetitive visual inspections to detect discrepancies of the slat 
universal joint and steady bearing assemblies, and replacement of any 
discrepancy assembly with a new, like assembly.
    The DGAC classified this service bulletin as mandatory and issued 
French airworthiness directive (CN) 95-074-179(B), dated April 26, 
1995, in order to assure the continued airworthiness of these airplanes 
in France.
    In addition, Lucas Liebherr has issued Service Bulletin 523-27-
M523-1, dated April 25, 1986, which describes procedures for 
replacement of all slat universal joint and steady bearing assemblies 
with new improved assemblies. Accomplishment of the replacement will 
eliminate the need for the repetitive inspections. The replacement will 
improve the reliability of the universal joint assemblies.

FAA's Conclusions -

    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 21.29) 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 the Proposed Requirements of the Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other airplanes of the same type design, the 
proposed AD would require repetitive visual inspections to detect 
discrepancies of the slat universal joint and steady bearing 
assemblies, and replacement of any discrepany assembly with a new, like 
assembly. The proposed AD also would require replacement of all slat 
universal joint and steady bearing assemblies with new assemblies, 
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 (CN) 95-074-179(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.

Cost Impact

    The FAA estimates that 26 Airbus Model A310 series airplanes of 
U.S. registry would be affected by this proposed AD.
    It would take approximately 5 work hours 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 proposed inspection on 
U.S. operators is estimated to be $7,800, or $300 per airplane, per 
inspection.
    It would take approximately 9 work hours per airplane to accomplish 
the proposed replacement, at an average labor rate of $60 per work 
hour. Required parts would cost approximately $48,108 per airplane. 
Based on these figures, the cost impact of the proposed replacement on 
U.S. operators is estimated to be $1,264,848, or $48,648 per airplane.
    The cost impact figure discussed above is 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

[[Page 20764]]

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), 40101, 40113, 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

Airbus Industrie: Docket 95-NM-241-AD
    Applicability: Model A310 series airplanes, on which Airbus 
Modification 6022 or 6485 has not been installed; 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 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 failure of the shaft of the slat transmission system, 
and subsequent uncommanded movement of the associated slat, 
accomplish the following:
    (a) Prior to the accumulation of 2,000 landings or 500 flight 
hours after the effective date of this AD, whichever occurs later, 
perform a visual inspection to detect discrepancies of the slat 
universal joint and steady bearing assemblies, in accordance with 
Airbus Service Bulletin A310-27-2040, Revision 2, dated January 5, 
1995.

    Note 2: Airbus Service Bulletin A310-27-2040 inadvertently 
references Lucas/Liebherr Service Bulletin 551A-27-6010 as the 
appropriate source for accomplishing the inspection. Lucas/Liebherr 
Service Bulletin 551A-27-610 is the appropriate source of 
information.
    (1) If no discrepancy is found, repeat the inspection thereafter 
at intervals not to exceed 2,000 landings.
    (2) If any discrepancy is detected and the groove depth on the 
shaft is greater than or equal to 1 mm (0.04 in.), prior to further 
flight, replace the discrepant bearing assembly with a new, like 
assembly, in accordance with the service bulletin. After 
replacement, repeat the visual inspection thereafter at intervals 
not to exceed 2,000 landings.
    (3) If any discrepancy is detected and the groove depth on the 
shaft is less than 1 mm (0.04 in.), prior to 50 landings after 
accomplishing the initial inspection, replace the discrepant bearing 
assembly with a new, like assembly, in accordance with the service 
bulletin. After the replacement, repeat the visual inspection 
thereafter at intervals not to exceed 2,000 landings.
    (b) Within 5 years after the effective date of this AD, replace 
the slat universal joint and steady bearing assemblies with new 
assemblies, in accordance with Lucas Liebherr Service Bulletin 523-
27-M523-1, dated April 25, 1986. Accomplishment of the replacement 
constitutes terminating action for the repetitive inspection 
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 May 2, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-11441 Filed 5-7-96; 8:45 am]
BILLING CODE 4910-13-U