AD 96-15-10

This amendment adopts a new airworthiness directive (AD), applicable to certain Fokker Model F28 Mark 0100 and 0070 series airplanes, that requires modification of the wheel brake assembly on the main landing gear. This amendment is prompted by reports of aluminum brake pistons that have ballooned and failed. The actions specified by this AD are intended to prevent such failure of the pistons, which could result in leakage of the hydraulic fluid, resultant loss of braking capability, and a possible brake fire.

Final rule

96-15-10 FOKKER: Amendment 39-9700. Docket 95-NM-171-AD.
Applicability: Model F28 Mark 0100 and 0070 series airplanes; equipped with Aircraft Braking Systems Corporation (ABSC) brake assemblies having part number (P/N) 5008132-2, -3, -4, -5, -6, or -7, all serial numbers; 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 loss of braking capability and possible brake fire due to failure of the brake pistons, accomplish the following:

(a) Within 9 months after the effective date of this AD, or at the next scheduled or unscheduled brake overhaul, whichever occurs first: Modify ABSC wheel brake assemblies having P/N 5008132-2, -3, -4, -5, -6, or -7, all serial numbers, by accomplishing either paragraph (a)(1) or (a)(2) of this AD.

(1) Replace the brake assemblies with modified units having stainless steel pistons, in accordance with the Accomplishment Instructions of Fokker Service Bulletin SBF100-32-092, dated January 11, 1995. Or

(2) Install a cylinder sleeve kit in accordance with Aircraft Braking Systems Service Bulletin Fo100-32-63, dated January 13, 1995.

(b) As of the effective date of this AD, no person shall install an ABSC brake assembly having part number 5008132-2, -3, -4, -5, -6, or -7, on any airplane unless it has been modified in accordance with Fokker Service Bulletin SBF100-32-092, dated January 11, 1995, or Aircraft Braking Systems Service Bulletin Fo100-32-63, dated January 13, 1995.

(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.

(e) The actions shall be done in accordance with Fokker Service Bulletin SBF100-32-092, dated January 11, 1995; and Aircraft Braking Systems Service Bulletin Fo100-32-63, dated January 13, 1995. 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 Fokker Aircraft USA, Inc., 1199 North Fairfax Street, Alexandria, Virginia 22314. Copies may be 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.

(f) This amendment becomes effective on September 3, 1996.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that is applicable to certain Fokker Model F28 Mark 0100 and 0070 series airplanes was published in the Federal Register on April 10, 1996 (61 FR 15908). That action proposed to require modification of the wheel brake assembly on the main landing gear (MLG).

Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received.

Support for the Proposal
One commenter supports the proposal.

Request to Withdraw the Proposal
The Air Transport Association (ATA) of America, on behalf of its member operators, has no technical objection to the proposal, but requests that the FAA withdraw the proposal if the entire affected U.S. fleet has been modified already. The ATA states that its one member operator affected by the proposal will accomplish the modification on all of its fleet within a short time. Consequently, the ATA questions the need for an AD when the fleet will be in compliance with the AD by the time the final rule is adopted.

The FAA does not concur with the commenter s request to withdraw the proposal. Even if the current U.S.-registered fleet may be in compliance with the requirements of the AD, the issuance of the rule is still necessary to ensure that any affected airplane that is imported and placed on the U.S. register in the future will be required to be in compliance as well. The manufacturer has advised the FAA that not all of the affected airplanes, worldwide, have been modified; therefore, the possibility exists that an unmodified airplane could be imported to the U.S. at some future time. Issuance of this AD will ensure that the airplane is modified prior to the time it is permitted to operate in the U.S.

Conclusion
After careful review of the available data, including the comments noted above, the FAA has determined that air safety and the public interest require the adoption of the rule as proposed.

Cost Impact
The FAA estimates that 122 airplanes of U.S. registry will be affected by this AD.

The replacement of the brake pistons, if accomplished, will take approximately 9 work hours per airplane
(when accomplished as part of a normal brake overhaul), at an average labor rate of $60 per work hour. Required parts will be provided by the manufacturer at no cost to operators. Based on these figures, the cost impact of this replacement action on U.S. operators is estimated to be $540 per airplane.

The installation of the cylinder sleeve kit, if accomplished, will take approximately 9 work hours per airplane (when accomplished as part of a normal brake overhaul), at an average labor rate of $60 per work hour. Required parts will cost approximately $4,400 per airplane. Based on these figures, the cost impact of this installation action on U.S. operatorsis estimated to be $4,940 per airplane.

The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted. However, the FAA has been advised that at least 40 affected airplanes already have been modified in accordance with the requirements of this AD; therefore, the future cost impact of the AD on U.S. operators is reduced by that amount.

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.

For the reasons discussed above, I certify that this action (1) is not a "significant regulatory action" under Executive Order 12866; (2) is not a "significant rule" under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) 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 final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it 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. Theauthority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.

39.13 - [Amended]
2. Section 39.13 is amended by adding the following new airworthiness directive: