Airworthiness Directives; Airbus Model A320-200 Series Airplanes

DEPARTMENT OF AGRICULTURE

DEPARTMENT OF TRANSPORTATION

14 CFR Part 39

[Docket No. 95-NM-267-AD]

RIN 2120-AA64

Airworthiness Directives; Airbus Model A320-200 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 A320-200

series airplanes. This proposal would require modification of the shock

absorber sub-assembly of the main landing gear (MLG). This proposal is

prompted by reports of internal damage to the shock absorber sub-

assembly due to loose screws in the upper bearing dowels. The actions

specified by the proposed AD are intended to prevent such damage, which

could result in the overextension of the shock absorber and failure of

the torque link. This situation may lead to the inability of the MLG to

retract and subsequent collapse of the MLG.

DATES: Comments must be received by June 10, 1996.

ADDRESSES: Submit comments in triplicate to the Federal Aviation

Administration (FAA), Transport Airplane Directorate, ANM-103,

Attention: Rules Docket No. 95-NM-267-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 Dowty Aerospace, Customer Support Center,

P.O. Box 49, Sterling, Virginia 20166.

This information may be examined at the FAA, Transport Airplane

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-267-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-267-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 A320-200 series

airplanes. The DGAC advises that it has received reports of internal

damage to the shock absorber sub-assembly of the main landing gear

(MLG). Investigation revealed that, due to an improper fit, the screws

in the upper bearing dowels of the shock absorber sub-assembly can

become loose and come out of position.

A loose screw in the upper bearing dowels can come out and cause

internal damage to the shock absorber tube assembly. If this were to

occur, the shock absorber sub-assembly may overextend and the torque

link may fail, which could result in the inability of the MLG to

retract and the subsequent collapse of the MLG.

Explanation of Relevant Service Information

Airbus has issued Service Bulletin A320-32-1144, dated December 8,

1994, which describes procedures for modification of the shock absorber

sub-assembly of the MLG. The modification involves installing new

dowels and a retaining ring to the shock absorber assembly. The

modification will reduce the possibility of internal damage to the sub-

assembly. (The Airbus service bulletin references Dowty Service

Bulletin 200-32-215, dated July 7, 1994, and Dowty Service Bulletin

200-32-216, Revision 1, dated August 4, 1994, as additional sources of

service information for accomplishment of these procedures.) The DGAC

classified this service bulletin as mandatory and issued French

airworthiness directive (CN) 95-016-063 (B), dated January 18, 1995, in

order to assure the continued airworthiness of these airplanes in

France.

[[Page 18705]]

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 the Requirements of the Proposed Rule

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 modification of the shock absorber sub-

assembly of the MLG. The actions would be required to be accomplished

in accordance with the service bulletin described previously.

Cost Impact

The FAA estimates that 115 airplanes of U.S. registry would be

affected by this proposed AD, that it would take approximately 24 work

hours per airplane to accomplish the proposed actions, and that the

average labor rate is $60 per work hour. Required parts would be

provided by the manufacturer at no cost to the operator. Based on these

figures, the cost impact of the proposed AD on U.S. operators is

estimated to be $165,600, or $1,440 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 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-267-AD.

Applicability: Model A320-200 series airplanes on which Airbus

Modification 24594 (reference Airbus Service Bulletin A320-32-1144)

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 (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 damage to the internal area of the shock absorber

sub-assembly, which could cause an overextension of the shock

absorber and failure of the torque link, accomplish the following:

(a) Prior to the accumulation of 6,000 total landings since the

shock absorber of the main landing gear (MLG) was removed, built, or

overhauled; or within 6 months after the effective date of this AD;

whichever occurs later: Modify the shock absorber assembly of the

MLG, in accordance with Airbus Service Bulletin A320-32-1144, dated

December 8, 1994.

Note 2: Airbus Service Bulletin A320-32-1144 references Dowty

Aerospace Service Bulletin 200-32-215, dated July 7, 1994, and Dowty

Aerospace Service Bulletin 200-32-216, Revision 1, dated November

18, 1994, as additional sources of service information for

modification of the shock absorber.

(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,

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 3: 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 April 23, 1996.

S.R. Miller,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 96-10507 Filed 4-26-96; 8:45 am]

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