[Federal Register Volume 61, Number 127 (Monday, July 1, 1996)]
[Proposed Rules]
[Pages 33874-33876]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-16651]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 96-NM-10-AD]
RIN 2120-AA64
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 inspections to detect cracking
of the upper radius of the forward fitting of frame 47, and repair, if
necessary. This proposal is prompted by results of full-scale fatigue
testing, which revealed cracking in the upper radius of frame 47. The
actions specified by the proposed AD are intended to prevent such
fatigue cracking, which could result in reduced structural integrity of
frame 47 of the fuselage.
DATES: Comments must be received by August 12, 1996.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 96-NM-10-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: Phil Forde, Aerospace Engineer,
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate,
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206)
227-2146; 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-10-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.
[[Page 33875]]
96-NM-10-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 all Airbus Model A300-600 series
airplanes. The DGAC advises that, during a full-scale fatigue test,
cracks were found on the left and right upper radius of frame 47 on a
Model A300 series airplane that had accumulated 48,000 flights. Similar
cracking also was found on an in-service Model A300 B2 series airplane
that had accumulated 18,000 flights. Fatigue cracking of the upper
radius could result in rupture of the forward fitting of the frame.
Such fatigue cracking, if not detected and corrected in a timely
manner, could result in reduced structural integrity of frame 47 of the
fuselage.
Explanation of Relevant Service Information
Airbus has issued Service Bulletin A300-53-6029, Revision 2, dated
November 7, 1994, which describes procedures for repetitive eddy
current inspections to detect cracking of the upper radius of the left
and right forward fitting of frame 47. For airplanes on which cracking
is found, the service bulletin describes procedures for modification of
the sealing fitting and sealing sham, and repetitive ultrasonic
inspections to detect cracking of the rear of the forward fitting.
Among other things, the modification involves performing PR sealing on
the fitting and on the fasteners inside the center wing box.
The DGAC classified this service bulletin as mandatory and issued
French airworthiness directive 93-162-148(B), dated September 15, 1993,
in order to assure the continued airworthiness of these airplanes in
France.
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 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 eddy
current inspections to detect cracking of the upper radius of the left
and right forward fitting of frame 47, and repair, if necessary. The
inspections would be required to be accomplished in accordance with the
service bulletin described previously. The repair would be required to
be accomplished in accordance with a method approved by the FAA.
Explanation of Differences Between Service Bulletin and Proposed
Rule
Operators should note that, unlike the procedures recommended in
the referenced service bulletin, this proposed rule would not permit
further flight after detection of cracking in the upper radius of the
fitting within certain limits. Instead, this proposed rule would
require, prior to further flight, repair of cracking in accordance with
a method approved by the FAA. The FAA finds that, in light of the
safety implications and consequences associated with such cracking, an
adequate level of safety for the affected fleet requires that cracking
in the upper radius must be repaired prior to further flight.
Additionally, this proposed AD does not require accomplishment of
the modification described in the referenced service bulletin. The
service bulletin specifies that purpose of the modification is to
provide access to the forward fitting of frame 47 to enable operators
to accomplish an ultrasonic inspection to detect longer cracks of the
rear of the fitting. The FAA finds that since accomplishment of this
modification will not prevent fatigue cracking of the upper radius, in
lieu of accomplishing that modification, any cracking detected during
the eddy current inspection must be repaired prior to further flight.
In addition, 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 manufacturers recommendation, but the
safety implications involved with cracking in the upper radius of the
fitting of frame 47 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.
Further, 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 upper radius of the fitting of
frame 47 is aggravated by landing operations, 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 4 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
$8,400, or $240 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
[[Page 33876]]
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 Industrie: Docket 96-NM-10-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 (b) 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 reduced structural integrity of frame 47 of the
fuselage, accomplish the following:
(a) Prior to the accumulation of 17,300 total landings, or
within one year after the effective date of this AD, whichever
occurs later: Perform an eddy current inspection to detect cracking
of the upper radius of the left and right forward fitting of frame
47, in accordance with Airbus Service Bulletin A300-53-6029,
Revision 2, dated November 7, 1994.
(1) If no cracking is found during an eddy current inspection:
Repeat the inspection thereafter at intervals not to exceed 6,600
landings.
(2) If any cracking is found during an eddy current inspection:
Prior to further flight, repair in accordance with a method approved
by the Manager, Standardization Branch, ANM-113, FAA, Transport
Airplane Directorate.
(b) 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.
(c) 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 June 25, 1996.
S.R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 96-16651 Filed 6-28-96; 8:45 am]
BILLING CODE 4910-13-P
