Airworthiness Directives; BFGoodrich Main Brake Assemblies as Installed on Airbus Model A319 and A320 Series Airplanes

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-NM-341-AD; Amendment 39-11450; AD 99-25-07]

RIN 2120-AA64

Airworthiness Directives; BFGoodrich Main Brake Assemblies as

Installed on Airbus Model A319 and A320 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that

is applicable to certain BFGoodrich main brake assemblies as installed

on Airbus Model A319 and A320 series airplanes. This action requires a

one-time inspection of the wear indicator pins to determine the level

of wear of the main brake assemblies of the main landing gear (MLG),

and corrective actions, if necessary. This action also requires

modification of the main brake assemblies of the MLG, and incorporation

of specified wear limits into the maintenance inspection program. This

amendment is prompted by in-service reports of brake deterioration

caused by thermal

[[Page 68621]]

oxidation of the carbon disks of certain BFGoodrich main brake

assemblies. The actions specified in this AD are intended to prevent

thermal oxidation of the main brake assemblies, which could result in

deterioration of the MLG brakes, and consequent reduced braking

performance.

DATES: Effective December 23, 1999.

The incorporation by reference of certain publications listed in

the regulations is approved by the Director of the Federal Register as

of December 23, 1999.

Comments for inclusion in the Rules Docket must be received on or

before January 7, 2000.

ADDRESSES: Submit comments in triplicate to the Federal Aviation

Administration (FAA), Transport Airplane Directorate, ANM-114,

Attention: Rules Docket No. 99-NM-341-AD, 1601 Lind Avenue, SW.,

Renton, Washington 98055-4056.

The service information referenced in this AD may be obtained from

BFGoodrich Aircraft Wheels and Brakes, P.O. Box 340, Troy, Ohio, 45373.

This information may be examined at the FAA, Transport Airplane

Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the

Office of the Federal Register, 800 North Capitol Street, NW., suite

700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Norman B. Martenson, Manager,

International Branch, ANM-116, FAA, Transport Airplane Directorate,

1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425)

227-2110; fax (425) 227-1149.

SUPPLEMENTARY INFORMATION: The FAA has received in-service reports of

brake deterioration of certain BFGoodrich main brake assemblies

installed on Airbus Model A319 and A320 series airplanes. Investigation

revealed that the deterioration of these BFGoodrich brakes was caused

by thermal oxidation of the carbon material due to exposure to elevated

temperatures for prolonged periods of time. Further investigation

revealed that the oxidation inhibitor process used by BFGoodrich does

not completely prevent oxidation of the carbon brake material.

BFGoodrich advises that these carbon brakes, which are susceptible to

this oxidation condition, are only used on Airbus Model A319 and A320

series airplanes. This condition, if not corrected, could result in

deterioration of the MLG brakes, and consequent reduced braking

performance.

Explanation of Relevant Service Information

BFGoodrich has issued Service Bulletins 2-1598-32-1, and 2-1600-32-

2, both dated November 5, 1999, which describe procedures for removal

of main brake assemblies with wear indicator pins having a length of

0.20 inch or less, and modification of the main brake assemblies of the

MLG. The modification involves reducing the length of the wear

indicator pins, and re-identifying the piston housings and

identification plates of the main brake assemblies.

FAA's Determination

The FAA has determined that a direct correlation exists between the

amount of wear and the degree of thermal oxidation. Therefore, by

limiting the wear of the carbon brake assemblies, as required by this

AD, thermal oxidation is controlled to an acceptable level.

FAA's Conclusions

These airplane models are manufactured in France and are 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.

Explanation of Requirements of 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, this AD is being issued to prevent thermal

oxidation of the main brake assemblies, which could result in

deterioration of the MLG brakes, and consequent reduced braking

performance. This AD requires one-time detailed visual inspection of

the wear indicator pins to determine the level of wear of the main

brake assemblies of the main landing gear (MLG), and corrective

actions, if necessary. This AD also requires modification of the main

brake assemblies of the MLG, and incorporation of specified wear limits

into the FAA-approved maintenance inspection program. Certain actions

are required to be accomplished in accordance with the service

bulletins described previously, except as discussed below.

Interim Action

This is considered to be interim action. The brake manufacturer has

advised that it currently is developing a modification that will

positively address the unsafe condition addressed by this AD. Once this

modification is developed, approved, and available, the FAA may

consider additional rulemaking.

Differences Between AD and Service Information

Operators should note that the BFGoodrich service bulletins allow

an option of either replacement of any main brake assembly with 0.20

inch or less remaining on the wear indicator pins, or modification of

the brake assembly by reducing the wear indicator pins. Additionally,

the BFGoodrich service bulletins do not recommend a compliance time for

either action. However, this AD requires a one-time inspection of the

wear indicator pins within 10 days, and replacement of the brake

assembly if the remaining length of the wear indicator pin is equal to

or less than 0.20 inch. This AD also requires modification of the brake

assembly to reduce the length of the wear indicator pins within 30

days, and re-identification of the piston housings and identification

plates no later than the next brake removal. The FAA finds that in view

of in-service reports of main brake assembly deterioration, the

requirements specified in this AD are appropriate to maintain a

consistent main brake assembly configuration for all airplanes that are

affected by the subject unsafe condition.

Determination of Rule's Effective Date

Since a situation exists that requires the immediate adoption of

this regulation, it is found that notice and opportunity for prior

public comment hereon are impracticable, and that good cause exists for

making this amendment effective in less than 30 days.

Comments Invited

Although this action is in the form of a final rule that involves

requirements affecting flight safety and, thus, was not preceded by

notice and an opportunity for public comment, comments are invited on

this rule. Interested persons are invited to comment on this 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 under the caption ADDRESSES. All

communications received on or before the closing date for comments will

be considered, and this rule may be amended in light of the comments

received. Factual information that supports the commenter's ideas and

suggestions is extremely helpful in evaluating the effectiveness of the

AD action and determining whether additional rulemaking action would be

needed.

[[Page 68622]]

Comments are specifically invited on the overall regulatory,

economic, environmental, and energy aspects of the rule that might

suggest a need to modify the 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 that

summarizes each FAA-public contact concerned with the substance of this

AD will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments

submitted in response to this rule must submit a self-addressed,

stamped postcard on which the following statement is made: ``Comments

to Docket Number 99-NM-341-AD.'' The postcard will be date stamped and

returned to the commenter.

Regulatory Impact

The regulations adopted herein will 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 final

rule does not have sufficient federalism implications to warrant the

preparation of a Federalism Assessment.

The FAA has determined that this regulation is an emergency

regulation that must be issued immediately to correct an unsafe

condition in aircraft, and that it is not a ``significant regulatory

action'' under Executive Order 12866. It has been determined further

that this action involves an emergency regulation under DOT Regulatory

Policies and Procedures (44 FR 11034, February 26, 1979). If it is

determined that this emergency regulation otherwise would be

significant under DOT Regulatory Policies and Procedures, a final

regulatory evaluation will be prepared and placed in the Rules Docket.

A copy of it, if filed, may be obtained from the Rules Docket at the

location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by

reference, Safety.

Adoption of the Amendment

Accordingly, pursuant to the authority delegated to me by the

Administrator, the Federal Aviation Administration amends 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:

99-25-07 BFGoodrich: Amendment 39-11450. Docket 99-NM-341-AD.

Applicability: BFGoodrich main brake assemblies having part

number (P/N) 2-1598 or 2-1600, as installed on Airbus Model A319 and

A320 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 thermal oxidation of the main brake assemblies of the

main landing gear (MLG), which could result in deterioration of the

MLG brakes, and consequent reduced braking performance, accomplish

the following:

Detailed Visual Inspection

(a) Within 10 days after the effective date of this AD, perform

a one-time detailed visual inspection of the wear indicator pins to

determine the level of wear of the main brake assemblies of the MLG,

as specified in BFGoodrich Service Bulletin 2-1598-32-1, or 2-1600-

32-2, both dated November 5, 1999, as applicable.

Note 2: For the purposes of this AD, a detailed visual

inspection is defined as: ``An intensive visual examination of a

specific structural area, system, installation, or assembly to

detect damage, failure, or irregularity. Available lighting is

normally supplemented with a direct source of good lighting at

intensity deemed appropriate by the inspector. Inspection aids such

as mirror, magnifying lenses, etc. may be used. Surface cleaning and

elaborate access procedures may be required.''

(1) If the remaining length of any wear indicator pin is less

than or equal to 0.20 inch (5.1 mm) with the brake pressurized,

prior to further flight, replace the brake assembly with a new or

serviceable brake assembly, in accordance with Chapter 32-42-27 of

the applicable Airplane Maintenance Manual (AMM).

(2) If the remaining length of all wear indicator pins is

greater than 0.20 inch (5.1 mm) with the brake pressurized, no

further action is required by this paragraph.

Modification

(b) Within 30 days after the effective date of this AD, modify

the main brake assemblies of the MLG by reducing the length of the

wear indicator pins, in accordance with BFGoodrich Service Bulletin

2-1598-32-1, or 2-1600-32-2, both dated November 5, 1999, as

applicable; and incorporate the new wear limits for the main brake

assemblies specified in the applicable service bulletin into the

FAA-approved maintenance program and comply with those limits

thereafter. After accomplishing the modification, but no later than

the next brake removal, re-identify the brake assemblies in

accordance with the applicable service bulletin.

Note 3: Once an operator has complied with the requirements of

paragraph (b) of this AD, that paragraph does not require that

operators subsequently record accomplishment of the requirements

each time a brake is inspected or overhauled in accordance with that

operator's FAA-approved maintenance inspection program.

Spares

(c) As of the effective date of this AD, no person shall install

on any airplane a BFGoodrich main brake assembly having P/N 2-1598

or 2-1600, unless that assembly has been modified in accordance with

this AD.

Alternative Methods of Compliance

(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, International Branch, ANM-116, 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, International

Branch, ANM-116.

Note 4: Information concerning the existence of approved

alternative methods of compliance with this AD, if any, may be

obtained from the International Branch, ANM-116.

Special Flight Permits

(e) Special flight permits may be issued in accordance with

Secs. 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.

Incorporation by Reference

(f) The actions shall be done in accordance with BFGoodrich

Service Bulletin 2-1598-32-1, dated November 5, 1999, or BFGoodrich

Service Bulletin 2-1600-32-2, dated November 5, 1999, as applicable.

This incorporation by reference was approved by the Director of the

Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part

51. Copies may be obtained from BFGoodrich Aircraft Wheels and

Brakes, P.O. Box 340, Troy, Ohio, 45373. Copies may be

[[Page 68623]]

inspected at the FAA, Transport Airplane Directorate, 1601 Lind

Avenue, SW., Renton, Washington; or at the Office of the Federal

Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

(g) This amendment becomes effective on December 23, 1999.

Issued in Renton, Washington, on November 24, 1999.

D.L. Riggin,

Acting Manager, Transport Airplane Directorate, Aircraft Certification

Service.

[FR Doc. 99-31474 Filed 12-7-99; 8:45 am]

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