AD 99-04-21

This amendment adopts a new airworthiness directive (AD) that applies all British Aerospace Jetstream Model 3101 airplanes that have a certain wheel assembly incorporated and all Jetstream Model 3201 airplanes that are equipped with Dunlop AH54450 brake units. This AD requires inspecting the main landing gear brake units for correct setting of the wear indicator pins, and re-setting the pins if incorrect. This AD is the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for the United Kingdom. The actions specified by this AD are intended to prevent failure of the main landing gear brakes because the wear indicator pins present a false indication of the remaining wear of the brake units, which could result in loss of control of the airplane during takeoff, landing, or taxi operations.

Final rule

99-04-21 BRITISH AEROSPACE: Amendment 39-11046; Docket No. 98-CE-76-AD.
Applicability: The following aircraft, certificated in any category:

- Jetstream Model 3101 airplanes, all serial numbers, that have Jetstream Kit JK12097 or Jetstream Service Bulletin 32-JK12097 incorporated; and

- Jetstream Model 3201 airplanes, all serial numbers, that are equipped with Dunlop AH54450 brake units.

NOTE 1: Jetstream Kit JK12097 and Jetstream Service Bulletin 32-JK12097 include the procedures necessary to incorporate J3200 series wheels with 12-ply rated tires and brakes for Jetstream Model 3101 airplanes.

NOTE 2: 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 in the body of this AD, unless already accomplished.

To prevent failure of the main landing gear brakes because the wear indicator pins present a false indication of the remaining wear of the brake units, which could result in loss of control of the airplane during takeoff, landing, or taxi operations, accomplish the following:

(a) Within the next 30 calendar days after the effective date of this AD, inspect the main landing gear brake units for correct setting of the wear indicator pins, in accordance with the instructions in PART 2 of British Aerospace Jetstream Alert ServiceBulletin 32-A- JA980540, ORIGINAL ISSUE: July 6, 1998. Prior to further flight, re-set the pins if the existing setting is incorrect, in accordance with the service bulletin.

(b) As of the effective date of this AD, no person may install Dunlop AH54450 brake units on any Jetstream Model 3201 airplane or incorporate Jetstream Kit JK12097 and Jetstream Service Bulletin 32-JK12097 on any Jetstream 3101 airplane, unless the inspection and possible follow-up requirements of paragraph (a) of this AD have been accomplished on the parts.

(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.

(d) An alternative method of compliance or adjustment of the compliance times that provides an equivalent level of safety may be approved by the Manager, Small Airplane Directorate, Aircraft CertificationService, 1201 Walnut, suite 900, Kansas City, Missouri 64106. The request shall be forwarded through an appropriate FAA Maintenance Inspector, who may add comments and then send it to the Manager, Small Airplane Directorate.

NOTE 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Small Airplane Directorate.

(e) Questions or technical information related to British Aerospace Jetstream Alert Service Bulletin 32-A-JA980540, ORIGINAL ISSUE: July 6, 1998, should be directed to British Aerospace Regional Aircraft, Prestwick International Airport, Ayrshire, KA9 2RW, Scotland; telephone: (01292) 479888; facsimile: (01292) 479703. This service information may be examined at the FAA, Central Region, Office of the Regional Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106.

(f) The inspection and modification required by this AD shall be done in accordance with British AerospaceJetstream Alert Service Bulletin 32-A-JA980540, ORIGINAL ISSUE: July 6, 1998. 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 British Aerospace Regional Aircraft, Prestwick International Airport, Ayrshire, KA9 2RW, Scotland. Copies may be inspected at the FAA, Central Region, Office of the Regional Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri, or at the Office of the Federal Register, 800 North Capitol Street, NW, suite 700, Washington, DC.

NOTE 4: The subject of this AD is addressed in British AD 003-07-98, dated July 13, 1998.

(g) This amendment becomes effective on April 2, 1999.

Events Leading to the Issuance of This AD
A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an AD that would apply to all British Aerospace Jetstream Model 3101 airplanes that have Jetstream Kit JK12097 or Jetstream Service Bulletin 32-JK12097 incorporated and all Jetstream Model 3201 airplanes that are equipped with Dunlop AH54450 main landing gear brake units was published in the Federal Register as a notice of proposed rulemaking (NPRM) on December 8, 1998 (63 FR 67629). The NPRM proposed to require inspecting the main landing gear brake units for correct setting of the wear indicator pins, and re-setting the pins if incorrect. Accomplishment of the proposed action as specified in the NPRM would be in accordance with British Aerospace Jetstream Alert Service Bulletin 32-A-JA980540, ORIGINAL ISSUE: July 6, 1998.

The NPRM was the result of mandatory continuing airworthiness information (MCAI) issued by theairworthiness authority for the United Kingdom.

Interested persons have been afforded an opportunity to participate in the making of this amendment. No comments were received on the proposed rule or the FAA's determination of the cost to the public.

The FAA's Determination
After careful review of all available information related to the subject presented above, the FAA has determined that air safety and the public interest require the adoption of the rule as proposed except for minor editorial corrections. The FAA has determined that these minor corrections will not change the meaning of the AD and will not add any additional burden upon the public than was already proposed.

Compliance Time of This AD
Although failure of the main landing gear brakes will only be unsafe while the airplane is in operation, the cause of this condition is not a result of the number of times the airplane is operated. The chance of the brake wear pin being incorrectly set is the same for an airplane with 10 hours time-in-service (TIS) as it is for an airplane with 1,000 hours TIS. For this reason, the FAA is utilizing a compliance based on calendar time in order to assure that the unsafe condition is addressed on all airplanes in a reasonable time period.

Cost Impact
The FAA estimates that 296 airplanes in the U.S. registry will be affected by this AD, that it will take approximately 3 workhours per airplane to accomplish the inspection, and that the average labor rate is approximately $60 an hour. Based on these figures, the total cost impact of the inspection on U.S. operators is estimated to be $53,280, or $180 per airplane.

The FAA has no way of determining the number of wear indicator pins that will be found incorrectly set, and will require re-setting. Therefore, the above figures only represent the inspection costs of this AD.

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 copy of the final 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, 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.

39.13 [Amended]
2. Section 39.13 is amended by adding a new airworthiness directive (AD) to read as follows: