[Federal Register Volume 60, Number 238 (Tuesday, December 12, 1995)]
[Proposed Rules]
[Pages 63665-63667]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-30212]



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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 95-NM-78-AD]


Airworthiness Directives; Airbus Model 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 A300-600 
series airplanes. This proposal would require inspections to detect 
corrosion and cracking of the lower horizontal-stabilizer cutout 
longeron, the corner fitting, the skin strap, and the outer skin; and 
repair, if necessary. This proposal is prompted by cracking found at 
the lower corner of the horizontal-stabilizer cutout longeron during a 
full scale fatigue test. The actions specified by the proposed AD are 
intended to prevent such cracking, which could result in reduced 
structural integrity of the horizontal stabilizer cutout longeron.

DATES: Comments must be received by January 23, 1996.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 95-NM-78-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) 
277-2589; 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. 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 


[[Page 63666]]
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-78-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-78-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 A300-600 series 
airplanes. The DGAC advises that, during a full-scale fatigue test, 
cracking was found on the test airplane at the lower corner of the 
horizontal-stabilizer cutout longeron, between frame (FR) 87 and FR89 
and between stringer (STGR) 24 and STGR27, left- and right-hand. The 
cracking was found after 87,675 simulated flights. Such fatigue 
cracking, if not corrected, could result in reduced structural 
integrity of the horizontal stablizer cutout longeron.
    Airbus has issued Service Bulletin A300-53-6042, Revision 1, dated 
February 20, 1995, which describes procedures for repetitive visual and 
eddy current inspections to detect corrosion and cracking of the lower 
horizontal-stabilizer cutout longeron, the corner fitting, the skin 
strap, and the outer skin between FR87 and FR89 and between STGR24 and 
STGR27, left- and right-hand; and repair, if necessary. The service 
bulletin also describes procedures for repetitive rotating probe 
inspections to detect cracks in the fastener holes at the same 
locations, and repair, if necessary. The service bulletin also 
describes procedures for certain follow-on actions, which include 
installing a new corner fitting, installing a new longeron, and 
performing a cold working procedure repairing cracks of certain 
measurements. The DGAC classified this service bulletin as mandatory 
and issued French airworthiness directive (CN) 94-269-171(B)R1, dated 
March 29, 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 21.29) 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.
    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 
and eddy current inspections to detect corrosion and fatigue cracking 
of the lower horizontal-stabilizer cutout longeron, the corner fitting, 
the skin strap, and the skin between FR87 and FR89 and between STGR24 
and STGR27, left-hand and right-hand. The proposed AD would also 
require repetitive rotating probe inspections to detect cracks in the 
fastener holes at the same locations; and repair or certain a follow-on 
actions, if necessary. The actions would be required to be accomplished 
in accordance with the service bulletin described previously. Certain 
repairs would be required to be accomplished in accordance with a 
method approved by the FAA.
    Operators should note that certain requirements of this proposed AD 
would differ from actions recommended in the referenced Airbus service 
bulletin. The service bulletin specifies that inspection thresholds and 
intervals may be adjusted based on certain average flight operations of 
the airplane. However, the FAA has determined that such adjustments 
would not address the unsafe condition in a timely manner. Therefore, 
this proposed AD does not permit such adjustments. In developing the 
appropriate compliance time for the proposed rule, the FAA considered 
not only the manufacturer's recommendation, but the safety implications 
involved with cracking of the horizontal-stabilizer cutout longeron and 
the number of landings that had been accumulated when cracking was 
detected. In light of these factors, the FAA finds the compliance times 
specified in the proposed AD for initiating the required actions to be 
warranted, in that they represent an appropriate interval of time 
allowable for the affected airplanes to continue to operate without 
compromising safety.
    Additionally, the service bulletin specifies that operators need 
not count touch-and-go landings in determining the total number of 
landings between two consecutive inspections, even if those landings 
are less than five percent of the landings between inspection 
intervals. Since the fatigue cracking that was found in the lower 
horizontal stabilizer cutout longeron is aggravated by landing, the FAA 
finds that all touch-and-go landings must be counted in determining the 
total number of landings between two consecutive inspections.
    The FAA estimates that 2 airplanes of U.S. registry would be 
affected by this proposed AD, that it would take approximately 268 work 
hours per airplane to accomplish the proposed actions, 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 
$32,160 to $16,080 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.
    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:

[[Page 63667]]


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 the following new 
airworthiness directive:

Airbus Industries: Docket 95-NM-78-AD.

    Applicability: Model A300-600 series airplanes on which Airbus 
Modification No. 6146 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 
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 use the authority 
provided in paragraph (f) of this AD to request approval from the 
FAA. This approval may address either no action, if the current 
configuration eliminates the unsafe condition; or different actions 
necessary to address the unsafe condition described in this AD. Such 
a request should include an assessment of the effect of the changed 
configuration on the unsafe condition addressed by this AD. In no 
case does the presence of any modification, alternation, or repair 
remove any airplane from the applicability of this AD.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent reduced structural integrity of the horizontal 
stabilizer cutout longeron due to fatigue cracking, accomplish the 
following:
    (a) Prior to the accumulation of 18,000 total landings, or 
within 2,000 landings after the effective date of this AD, whichever 
occurs later: Perform a visual and an eddy current inspection to 
detect cracks and/or corrosion of Areas 1 and 2 of the lower 
horizontal stabilizer cutout longeron, as defined in Airbus Service 
Bulletin A300-53-6042, Revision 1, and dated February 20, 1995. 
Perform the inspections in accordance with the service bulletin.
    (b) Perform a visual and an eddy current inspection to detect 
cracks and/or corrosion of Area 3 of the lower horizontal-stabilizer 
cutout longeron, as defined in Airbus Service Bulletin A300-53-6042, 
Revision 1, dated February 20, 1995. Perform these inspections in 
accordance with the service bulletin, at the later of the times 
specified in paragraph (b)(1) and (b)(2) of this AD.
    (1) Prior to the accumulation of 24,000 total landings, but not 
before the accumulation of 18,000 total landings; or
    (2) Prior to the accumulation of 2,000 landings after the 
effective date of this AD.
    (c) If no cracking is detected during any inspection required by 
this AD: Prior to further flight, cold work and ream the vacated 
fastener holes, in accordance with Airbus Service Bulletin A300-53-
6042, Revision 1, dated February 20, 1995; and perform the 
requirements of paragraph (c)(1) or (c)(2) of this AD, as 
applicable.
    (1) For airplanes on which no cracking is found in Area 1 or 2: 
Repeat the inspections required by paragraph (a) of this AD 
thereafter at intervals not to exceed 6,000 flight cycles.
    (2) For airplanes on which no cracking is found in Area 3: 
Perform the various follow-on actions in accordance with the service 
bulletin. (The follow-on actions include installing a new corner 
fitting, installing a new longeron and performing a cold working 
procedure.) After accomplishment of these follow-on actions, no 
further action is required by this AD.
    (d) If any cracking is detected during any inspection required 
by this AD, perform the requirements of paragraph (d)(1) or (d)(2) 
of this AD, as applicable.
    (1) If any cracking is found in Area 1 or 3 that is within the 
limits specified in Airbus Service bulletin A300-53-6042, Revision 
1, dated February 20, 1995: Prior to further flight, repair in 
accordance with the service bulletin.
    (2) If any cracking is found in Area 2, or if any cracking is 
found in any area and that cracking is beyond the limits described 
in Airbus Service Bulletin A300-53-6042, Revision 1, dated February 
20, 1995: Prior to further fight, repair in accordance with a method 
approved by the Manager, Standardization Branch, ANM-113, FAA, 
Transport Airplane Directorate.
    (e) If any corrosion is detected during any inspection required 
by this AD, prior to further flight, repair the corrosion in 
accordance with Airbus Service Bulletin A300-53-6042, Revision 1, 
dated February 20, 1995.
    (f) 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. 
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.

    (g) 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 December 6, 1995.
Darrell M. Pederson,
Acting Manger, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 95-30212 Filed 12-11-95; 8:45 am]
BILLING CODE 4910-13-M