[Federal Register Volume 61, Number 77 (Friday, April 19, 1996)]
[Proposed Rules]
[Pages 17257-17259]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-9692]



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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 95-NM-249-AD]


Airworthiness Directives; Airbus Model A320-111, -211, and -231 
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 A320-111, -
211, and -231 series airplanes. This proposal would require visual 
inspections to detect cracks of the fittings of the pressurized floor 
at frame 36, and renewal of the zone protective finish or replacement 
of fittings with new fittings, if necessary. This proposal is prompted 
by a report of fatigue cracking found on the pressurized floor fitting 
at frame 36 under the lower surface panel. The actions specified by the 
proposed AD are intended to prevent such fatigue cracking, which could 
result in failure of a floor fitting and subsequent depressurization of 
the fuselage.

DATES: Comments must be received by May 31, 1996.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 95-NM-249-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

[[Page 17258]]

Directorate, 1601 Lind Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT: Tim Backman, Aerospace Engineer, 
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 
1601 Lind Avenue SW., Renton, Washington 98055-4056; telephone (206) 
227-2797; 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 95-NM-249-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-249-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 A320-111, -211, and 
-231 series airplanes. The DGAC advises that, during a full-scale 
fatigue test on a center fuselage test article, cracking occurred on 
the pressurized floor fitting at frame 36 under the lower surface pane 
after the accumulation of 102,560 simulated flights. The cracking has 
been attributed to fatigue. Such fatigue cracking, if not detected and 
corrected in a timely manner, could result in failure of a fitting and 
subsequent depressurization of the fuselage.
    Airbus has issued Service Bulletin A320-57-1028, dated August 12, 
1991, which describes procedures for visual inspections to detect 
cracks of the six fittings of the pressurized floor at frame 36 under 
the lower surface panel, and renewal of the zone protective finish, if 
necessary. For cases where the length of the cracking is outside 
certain limits, the service bulletin describes procedures for 
replacement of all cracked fittings with new fittings. However, the 
service bulletin permits further flight, under certain conditions, with 
a fitting(s) that is cracked and the length of the cracking within 
certain limits. The DGAC classified this service bulletin as mandatory 
and issued French airworthiness directive 95-099-067(B), dated May 24, 
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, the 
proposed AD would require visual inspection(s) to detect cracks of the 
six fittings of the pressurized floor at frame 36 under the lower 
surface panel, and renewing the zone protective finish or replacement 
of the fittings with new fittings, if necessary. The actions would be 
required to be accomplished in accordance with the service bulletin 
described previously.
    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 any fitting. The FAA has determined 
that, due to safety implications and consequences associated with such 
cracking, the subject fittings that are found to be cracked must be 
replaced. Therefore, for cases where one fitting is cracked and the 
length of the cracking is outside certain limits, or where two or more 
fittings are cracked, the proposed AD would require replacement of all 
six fittings with new fittings. For cases where one fitting is cracked 
and the length of the cracking is within certain limits, the proposed 
AD would require replacement of that fitting prior to further flight, 
and eventual replacement of the remaining five fittings. The 
replacement procedures are provided in the service bulletin described 
previously.
    The FAA estimates that 22 Airbus Model A320-111, -211, and -231 
series airplanes of U.S. registry would be affected by this proposed 
AD, that it would take approximately 3 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 $3,960, or $180 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 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.

[[Page 17259]]

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 95-NM-249-AD.

    Applicability: Model A320-111, -211, and -231 series airplanes; 
manufacturer's serial numbers 002 through 008 inclusive, 010 through 
014 inclusive, 016 through 078 inclusive, and 080 through 104 
inclusive; on which Airbus Modification 21282P01497 (reference 
Airbus Service Bulletin A320-57-1029) 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 
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 prevent fatigue cracking on the pressurized floor fitting at 
frame 36 under the lower surface panel, which could result in 
failure of a fitting and subsequent depressurization of the 
fuselage, accomplish the following:
    (a) Prior to the accumulation of 16,000 total landings, or 
within 6 months after the effective date of this AD, whichever 
occurs later, perform a visual inspection to detect cracks of the 6 
fittings of the pressurized floor at frame 36 under the lower 
surface panel, in accordance with Airbus Service Bulletin A320-57-
1028, dated August 12, 1991.
    (1) If no cracking is found, prior to further flight, renew the 
zone protective finish in accordance with the service bulletin. 
Repeat the visual inspection thereafter at intervals not to exceed 
12,000 landings.
    (2) If only 1 of the 6 fittings is found to be cracked and that 
crack is less than or equal to 0.59 inch (15 mm) in length, prior to 
further flight, replace the cracked fitting with a new fitting in 
accordance with the service bulletin. Thereafter, prior to the 
accumulation of 500 landings following accomplishment of this 
replacement, replace the remaining 5 fittings with new fittings in 
accordance with the service bulletin.
    (3) If only 1 of the 6 fittings is found to be cracked and that 
crack is greater than 0.59 inch (15 mm) in length, prior to further 
flight, replace all six fittings with new fittings in accordance 
with the service bulletin.
    (4) If 2 or more fittings are found to be cracked, prior to 
further flight, replace all 6 fittings with new fittings in 
accordance with the service bulletin.
    (b) Replacement of all 6 fittings with new fittings in 
accordance with Airbus Service Bulletin A320-57-1028, dated August 
12, 1991, constitutes terminating action for the inspection 
requirements of this AD.
    (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 April 15, 1996.
S.R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-9692 Filed 4-18-96; 8:45 am]
BILLING CODE 4910-13-U