[Federal Register Volume 62, Number 62 (Tuesday, April 1, 1997)]
[Proposed Rules]
[Pages 15439-15441]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-8251]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 96-NM-172-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 a visual 
inspection to detect cracks in the aft mount beam assembly of the 
engine; and replacement of any cracked beam with a new beam or beam 
assembly. The proposal also would require a fluorescent penetrant 
inspection to detect cracks in the aft mount beam assembly of the 
engine, and various follow-on actions. This proposal is prompted by 
reports indicating that, apparently due to manufacturing defects during 
the forging process, cracking was found in two engine aft mount beams. 
The actions specified by the proposed AD are intended to detect and 
correct such cracking, which could result in reduced structural 
integrity of the aft mount beam assembly of the engine.

DATES: Comments must be received by May 12, 1997.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 96-NM-172-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; or Pratt & Whitney, 400 Main Street, East 
Hartford, Connecticut 06108. 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 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-172-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. 96-NM-172-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The Direction Generale de l'Aviation Civile (DGAC), which is the

[[Page 15440]]

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 it has received reports indicating 
that, during overhaul maintenance following a fluorescent penetrant 
inspection, cracking was found in two engine aft mount beams on Airbus 
Model A310 series airplanes. One of the beams had a long surface crack, 
and the other beam had smaller branch cracks. The apparent cause of 
such cracking has been attributed to the forging process during 
manufacturing. Cracking in the aft mount beam assembly of the engine, 
if not detected and corrected, could result in reduced structural 
integrity of the aft mount beam assembly.

Explanation of Relevant Service Information

    Pratt & Whitney has issued Alert Service Bulletin PW7R4 A71-129, 
Revision 1, dated August 30, 1995, and Service Bulletin PW4NAC A71-149, 
Revision 1, dated August 30, 1995. These service bulletins describe 
procedures for performing a visual inspection to detect cracks in the 
aft mount beam assembly of the engine; and replacement of any cracked 
beam with a new beam or beam assembly. These service bulletins also 
describe procedures for performing a fluorescent penetrant inspection 
to detect cracks in the aft mount beam assembly of the engine, and 
various follow-on actions. (These follow-on actions include an eddy 
current inspection, reidentification of the beam, and replacement of 
any cracked beam.) The DGAC classified these service bulletins as 
mandatory and issued French airworthiness directive (C/N) 96-020-
195(B), dated January 31, 1996, 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 
Sec. 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 a visual inspection 
to detect cracks in the aft mount beam assembly of the engine; and 
replacement of any cracked beam with a new beam or beam assembly. The 
proposed AD also would require a fluorescent penetrant inspection to 
detect cracks in the aft mount beam assembly of the engine, and various 
follow-on actions. The actions would be required to be accomplished in 
accordance with the applicable service bulletin described previously.

Cost Impact

    The FAA estimates that 8 Airbus Model A310 and A300-6000 series 
airplanes of U.S. registry would be affected by this proposed AD.
    It would take approximately 2 work hours per airplane to accomplish 
the proposed visual inspection, at an average labor rate of $60 per 
work hour. Based on these figures, the cost impact of the visual 
inspection proposed by this AD on U.S. operators is estimated to be 
$960, or $120 per airplane.
    It would take approximately 34 work hours per airplane to 
accomplish the proposed fluorescent penetrant inspection, at an average 
labor rate of $60 per work hour. Based on these figures, the cost 
impact of the flourescent penetrant inspection proposed by this AD on 
U.S. operators is estimated to be $16,320, or $2,040 per airplane.
    The cost impact figures discussed above are 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 Industrie: Docket 96-NM-172-AD.

    Applicability: Model A310 and A300-600 series airplanes, 
equipped with Pratt & Whitney Model JT9D-7R4D1, JT9D-7R4E1, JT9D-
7R4H1, PW4151, PW4156A, PW4158 engines; 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 (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 cracking in the aft mount beam assembly of 
the engine, which could result in reduced structural integrity of 
the aft mount beam assembly, accomplish the following:
    (a) Within 500 flight hours after the effective date of this AD, 
perform a visual inspection to detect cracks in the aft mount

[[Page 15441]]

beam assembly of the engine, in accordance with Part 1 of the 
Accomplishment Instructions of Pratt & Whitney Alert Service 
Bulletin PW7R4 A71-129, Revision 1, dated August 30, 1995, or Pratt 
& Whitney Service Bulletin PW4NAC A71-149, Revision 1, dated August 
30, 1995; as applicable.
    (1) If no crack is detected, no further action is required by 
this paragraph.
    (2) If any crack is detected, prior to further flight, replace 
the cracked beam with a new beam or beam assembly, in accordance 
with the applicable service bulletin.
    (b) Within 4,000 flight cycles after the effective date of this 
AD, perform a fluorescent penetrant inspection to detect cracks in 
the aft mount beam assembly of the engine, in accordance with Part 2 
of the Accomplishment Instructions of Pratt & Whitney Alert Service 
Bulletin PW7R4 A71-129, Revision 1, dated August 30, 1995, or Pratt 
& Whitney Service Bulletin PW4NAC A71-149, Revision 1, dated August 
30, 1995; as applicable.
    (1) If no crack is detected, prior to further flight, perform an 
eddy current inspection to detect cracks in the aft mount beam 
assembly of the engine, in accordance with the applicable service 
bulletin.
    (i) If no crack is detected, prior to further flight, reidentify 
the beam in accordance with the applicable service bulletin.
    (ii) If any crack is detected, prior to further flight, replace 
the cracked beam with a new beam or beam assembly, in accordance 
with the applicable service bulletin.
    (2) If any crack is detected, prior to further flight, replace 
the cracked beam with a new beam or beam assembly, in accordance 
with the applicable service bulletin.
    (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 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.

    (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 March 26, 1997.
S.R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 97-8251 Filed 3-31-97; 8:45 am]
BILLING CODE 4910-13-U