[Federal Register Volume 61, Number 45 (Wednesday, March 6, 1996)]
[Proposed Rules]
[Pages 8897-8899]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-5221]



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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 95-NM-150-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 all Airbus Model A300-600 series 
airplanes. This proposal would require an eddy current inspection to 
detect cracks on the forward fittings in the radius of frame 40 
adjacent to the tension bolts in the center section of the wings, and 
various follow-on actions. This proposal is prompted by reports of 
cracking in the radius of frame 40 adjacent to the tension bolts at the 
center/outer wing junction due to fatigue-related stress. The actions 
specified by the proposed AD are intended to prevent such fatigue-
related cracking, which could result in reduced structural integrity of 
the wings.

DATES: Comments must be received by April 12, 1996.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 95-NM-150-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 

[[Page 8898]]
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-150-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-150-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    On January 15, 1993, the FAA issued AD 93-01-24, Amendment 39-8478 
(58 FR 6703, February 2, 1993), which is applicable to all Airbus Model 
A300 B2, B4-100, and B4-200 series airplanes. That AD requires 
supplemental structural inspections to detect fatigue cracking, and 
repair or replacement, if necessary; or the installation of specific 
modifications. That action was prompted by a structural reevaluation, 
which identified certain significant structural components to inspect 
for fatigue cracks as these airplanes approach and exceed the 
manufacturer's original fatigue design life goal. The requirements of 
that AD are intended to prevent reduced structural integrity of these 
airplanes.
    Since the issuance of that AD, 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 all 
Airbus Model A300-600 series airplanes. The DGAC advises that, during 
sampling inspections required by AD 93-01-24, cracking was found in the 
radius of frame 40 adjacent to the tension bolts at the center/outer 
wing junction. The cracking occurred on Model A300 B2 and B4 series 
airplanes that had accumulated between 15,000 and 24,000 total flight 
cycles. The cause of such cracking has been attributed to fatigue-
related stress. Such fatigue-related cracking, if not corrected, could 
result in reduced structural integrity of the wings.
    The subject area on certain Model A300-600 series airplanes is 
almost identical to that on the affected Model A300 B2 and B4 series 
airplanes. Therefore, those Model A300-600 series airplanes may be 
subject to the same unsafe condition revealed on the Model A300 B2 and 
B4 series airplanes.

Explanation of Relevant Service Information

    Airbus has issued Service Bulletin A300-57-6062, dated February 14, 
1995, which describes procedures for an eddy current inspection to 
detect cracks on the forward fittings in the radius of frame 40 
adjacent to the tension bolts in the center section of the wings, and 
various follow-on actions. (These follow-on actions include applying a 
sealant, eddy current inspections, and blending of cracks.) This 
service bulletin permits further flight, under certain conditions, with 
forward fittings that are cracked within certain limits. The DGAC 
classified this service bulletin as mandatory and issued French 
airworthiness directive 95-063-177(B), dated April 12, 1995, in order 
to assure the continued airworthiness of these airplanes in France.

Explanation of the Proposed Rule

    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, the 
proposed AD would require an eddy current inspection to detect cracks 
on the forward fittings in the radius of frame 40 adjacent to the 
tension bolts in the center section of the wings, and various follow-on 
actions. The actions would be required to be accomplished in accordance 
with the service bulletin described previously.

Differences Between the Proposed Rule and Relevant Service 
Information

    Operators should note that, unlike the procedures described in the 
referenced service bulletin, this proposed AD would not permit further 
flight with cracking detected in the forward fittings. The FAA has 
determined that, due to the safety implications and consequences 
associated with such cracking under certain conditions, the subject 
forward fittings that are found to be cracked must be repaired. In 
addition, if any crack is removed and the blend out is greater than 50 
mm long and/or 2 mm deep, the forward fitting must be repaired. These 
repairs would be required to be accomplished in accordance with a 
method approved by the FAA.
    In addition, the service bulletin specifies that inspection 
thresholds and intervals should be adjusted based on the average 
utilization rate of the airplane. However, the FAA has determined that, 
in some cases, 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 inspection thresholds and 
intervals for the proposed rule, the FAA considered not only the 
manufacturer's recommendation and the average utilization rate of the 
affected U.S. registered airplanes, but the safety implications 
involved with cracking in the radius of frame 40 adjacent to the 
tension bolts at the center/outer wing junction. 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.
    Furthermore, 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 
fatigue cracking that was found in the radius of frame 40 adjacent to 
the tension bolts at the center/outer wing 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.

Cost Impact

    The FAA estimates that 35 airplanes of U.S. registry would be 
affected by this proposed AD, that it would take approximately 22 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 
$46,200, or $1,320 per airplane, per inspection cycle.
    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 

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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 95-NM-150-AD.

    Applicability: All Model A300-600 series airplanes, 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 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 fatigue-related cracking, which could result in 
reduced structural integrity of the wing, accomplish the following:
    (a) Perform an eddy current inspection to detect cracks on the 
forward fittings in the radius of frame 40 adjacent to the tension 
bolts in the center section of the wings, in accordance with Airbus 
Service Bulletin A300-57-6062, dated February 14, 1995, at the 
applicable time specified in either paragraph (a)(1) or (a)(2) of 
this AD.
    (1) For airplanes that have accumulated 12,400 total landings or 
less as of the effective date of this AD: Inspect prior to the 
accumulation of 10,500 total landings, or within 1,500 landings 
after the effective date of this AD, whichever occurs later.
    (2) For airplanes that have accumulated more than 12,400 total 
landings as of the effective date of this AD: Inspect within 750 
landings after the effective date of this AD.
    (b) If no crack is detected during the inspection required by 
paragraph (a) of this AD, prior to further flight, apply sealant, in 
accordance with Airbus Service Bulletin A300-57-6062, dated February 
14, 1995. Repeat the eddy current inspection thereafter at intervals 
not to exceed 4,500 landings.
    (c) If any crack is detected during the inspection required by 
paragraph (a) of this AD, prior to further flight, blend it out in 
accordance with Airbus Service Bulletin A300-57-6062, dated February 
14, 1995. Prior to further flight after accomplishing the blend out, 
perform an eddy current inspection to verify that the crack has been 
removed, in accordance with the service bulletin.
    (1) If any crack is removed and the blend out is equal to or 
less than 50 mm long and/or 2 mm deep, repeat the eddy current 
inspection required by paragraph (a) of this AD thereafter at 
intervals not to exceed 950 landings.
    (2) If any crack exists, or if any crack is removed and the 
blend out is more than 50 mm long and/or 2 mm deep, prior to further 
flight, repair in accordance with a method approved by the Manager, 
Standardization Branch, ANM-113, FAA, Transport Airplane 
Directorate.
    (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. 
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.

    Issued in Renton, Washington, on February 27, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-5221 Filed 3-5-96; 8:45 am]
BILLING CODE 4910-13-P