[Federal Register: March 20, 1998 (Volume 63, Number 54)]
[Proposed Rules]               
[Page 13572-13574]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr20mr98-39]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-17-AD]
RIN 2120-AA64

 
Airworthiness Directives; Airbus Model A310 and A300-600 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 and 
A300-600 series airplanes. This proposal would require repetitive 
visual inspections to detect corrosion on the lower rim area of the 
fuselage rear pressure bulkhead; and follow-on actions, if necessary. 
This proposal is prompted by issuance of mandatory continuing 
airworthiness information by a foreign civil airworthiness authority. 
The actions specified by the proposed AD are intended to detect and 
correct corrosion at the lower rim area of the fuselage rear pressure 
bulkhead, which could result in reduced structural integrity of the 
bulkhead, and consequent decompression of the cabin.

DATES: Comments must be received by April 20, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 98-NM-17-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: Norman B. Martenson, Manager, 
International Branch, ANM-116, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
227-2110; fax (425) 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 98-NM-17-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-114, Attention: Rules 
Docket No. 98-NM-17-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, notified the FAA that an unsafe 
condition may exist on certain Airbus Model A310 and A300-600 series 
airplanes. The DGAC advises that, during routine maintenance, severe

[[Page 13573]]

corrosion was found in the lower rim area of the aft pressure bulkhead 
between stringer 27, on the left- and right-hand sides of the airplane. 
The corrosion was found in two separate areas: on the inner rim angle 
of the bulkhead in the area of the drainhole, and in the cleat profile 
splice at the airplane centerline. The corrosion on the inner rim angle 
of the bulkhead has been attributed to damage of the surface protection 
when cleaning the drainholes or during the modifications specified in 
Airbus Service Bulletin A310-53-2025 or A300-53-6006. The corrosion of 
the cleat profile splice has been attributed to clogged drainholes or 
incomplete adhesion of sealant during accomplishment of the 
modifications specified in the service bulletins. Such corrosion, if 
not detected and corrected in a timely manner, could result in reduced 
structural integrity of the bulkhead, and consequent decompression of 
the cabin.

Explanation of Relevant Service Information

    The manufacturer has issued Airbus Service Bulletins A310-53-2092 
(for Model A310 series airplanes) and A300-53-6066 (for Model A300-600 
series airplanes), both dated October 16, 1996. These service bulletins 
describe procedures for repetitive visual inspections to detect 
corrosion on the lower rim area of the fuselage rear pressure bulkhead; 
and follow-on corrective actions (which include removal of corrosion 
and repair), if necessary. The DGAC classified these service bulletins 
as mandatory and issued French airworthiness directive 97-061-212(B), 
dated February 26, 1997, in order to assure the continued airworthiness 
of these airplanes in France.

FAA's Conclusions

    These airplane models are manufactured in France and are 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 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 accomplishment of 
the actions specified in the service bulletins described previously, 
except as discussed below.

Differences Between Proposed Rule and Service Bulletins

    Operators should note that, unlike the procedures previously 
described in Airbus Service Bulletins A310-53-2092 (for Model A310 
series airplanes) and A300-53-6066 (for Model A300-600 series 
airplanes), both dated October 16, 1996, this proposed AD would not 
permit further flight if corrosion is detected. The FAA has determined 
that, because of the safety implications and consequences associated 
with such corrosion, any subject part of the fuselage and aft pressure 
bulkhead that is found to have corrosion must be repaired prior to 
further flight.

Cost Impact

    The FAA estimates that 90 airplanes of U.S. registry would be 
affected by this proposed AD, that it would take approximately 62 work 
hours per airplane to accomplish the proposed inspection, and that the 
average labor rate is $60 per work hour. Based on these figures, the 
cost impact of the proposed AD on U.S. operators is estimated to be 
$334,800, or $3,720 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 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 U.S.C. 106(g), 40113, 44701.

Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:
    AIRBUS:  Docket 98-NM-17-AD.
    Applicability: Model A310 and A300-600 series airplanes on which 
Airbus Modification 6788 has not been accomplished; 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 detect and correct corrosion at the lower rim area of the 
fuselage rear pressure bulkhead, which could result in reduced 
structural integrity of the bulkhead, and consequent decompression 
of the cabin, accomplish the following:
    (a) Within 18 months after the effective date of this AD: Except 
as provided by paragraph (b) of this AD, perform a visual inspection 
to detect corrosion of the lower rim area of the aft pressure 
bulkhead, in accordance with Airbus Service Bulletin A310-53-2092 
(for Model A310 series

[[Page 13574]]

airplanes) or Airbus Service Bulletin A300-53-6066 (for Model A300-
600 series airplanes), both dated October 16, 1996, as applicable. 
If any discrepancy is found, prior to further flight, repair in 
accordance with the applicable service bulletin. Thereafter, repeat 
the inspection at the interval specified in paragraph (a)(1) or 
(a)(2), as applicable.
    (1) For airplanes on which Airbus Service Bulletin A310-53-2036 
or A300-53-6017 has not been accomplished: Repeat the inspection at 
intervals not to exceed 3 years.
    (2) For airplanes on which Airbus Service Bulletin A310-53-2036 
or A300-53-6017 has been accomplished: Repeat the inspection at 
intervals not to exceed 5 years.
    (b) If any discrepancy is found during an inspection required by 
paragraph (a) of this AD, and the applicable service bulletin 
specifies to contact Airbus for appropriate action: Prior to further 
flight, repair in accordance with a method approved by the Manager, 
International Branch, ANM-116, FAA, Transport Airplane Directorate.
    (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, International Branch, ANM-116. 
Operators shall submit their requests through an appropriate FAA 
Principal Maintenance Inspector, who may add comments and then send 
it to the Manager, International Branch, ANM-116.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the International Branch, ANM-116.

    (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.

    Note 3: The subject of this AD is addressed in French 
airworthiness directive 97-061-212(B), dated February 26, 1997.

    Issued in Renton, Washington, on March 13, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 98-7223 Filed 3-19-98; 8:45 am]
BILLING CODE 4910-13-U