AD 99-15-11

This amendment adopts a new airworthiness directive (AD) that applies to all British Aerospace HP137 Mk1, Jetstream series 200, and Jetstream Models 3101 and 3201 airplanes. This AD requires repetitively removing the nose landing gear steering selector valve and installing either a new nose landing gear steering selector valve or one that has been overhauled in accordance with the appropriate component maintenance manual. 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 the inability to steer the airplane because of wear in the nose landing gear steering selector differential, which could result in loss of control of the airplane during take-off, landing, or taxi operations.

Final rule.

99-15-11 BRITISH AEROSPACE: Amendment 39-11231; Docket No. 98-CE-115-AD.
Applicability: HP137 Mk1, Jetstream Series 200, and Jetstream Models 3101 and 3201 airplanes, 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 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: Upon accumulating 10,000 hours time-in-service (TIS) on the nose landing gear selector valve or within the next 12 calendar months after the effective date of this AD, whichever occurs later, unless already accomplished; and thereafter each time 10,000 hours TIS is accumulated on a nose landing gear selector valve.

To prevent the inability to steer the airplane because of wear in the nose landing gear steering selector differential, which could result in loss of control of the airplane during take-off, landing, or taxi operations, accomplish the following:

(a) Remove the nose landing gear steering selector valve, part number (P/N) 8668C or AIR86002-0 (or FAA-approved equivalent part number), and install one of the following in accordance with the applicable maintenance manual, as specified in British Aerospace Jetstream Service Bulletin 32-JA980841, Original Issue: October 28, 1998:

(1) A new steering selector valve, P/N 8668C or AIR86002-0 (or FAA-approved equivalent part number); or

(2) An FAA-approved nose landing gear steering selector valve that has been overhauled in accordance with the appropriate component maintenance manual.

NOTE 2: The FAA is requiring in another action (Docket No. 98-CE-117-AD) a one-time inspection of the nose wheel steering system to assure that the free play between the steering handle or knob and the nose wheels is within acceptable limits, with adjustment as necessary.

(b) 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.

(c) An alternative method of compliance or adjustment of the initial or repetitive compliance times that provides an equivalent level of safety may be approved by the Manager, Small Airplane Directorate, Aircraft Certification Service, 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.

(d) Questions or technical information related to British Aerospace Jetstream Service Bulletin 32-JA980841, Original Issue: October 28, 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.

NOTE 4: The subject of this AD is addressed inBritish Aerospace Jetstream Alert Service Bulletin 32-JA980841, Original Issue: October 28, 1998. This service bulletin is classified as mandatory by the United Kingdom Civil Aviation Authority (CAA).

(e) This amendment becomes effective on September 10, 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 HP137 Mk1, Jetstream series 200, and Jetstream Models 3101 and 3201 airplanes was published in the Federal Register as a notice of proposed rulemaking (NPRM) on April 23, 1999 (64 FR 19936). The NPRM proposed to require repetitively removing the nose landing gear steering selector valve and installing either a new nose landing gear steering selector valve or one that has been overhauled in accordance with the appropriate component maintenance manual.

Accomplishment of the proposed action as specified in the NPRM would be required in accordance with the applicable maintenance manual, as specified in British Aerospace Jetstream Service Bulletin 32-JA980841, Original Issue: October 28, 1998.

The FAA is requiring in another action (Docket No. 98-CE-117-AD) a one-time inspection of the nose wheel steering system to assure that the free play between the steering handle or knob and the nose wheels is within acceptable limits, with adjustment as necessary.

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

Interested persons have been afforded an opportunity to participate in the making of this amendment. One comment was received in favor of the NPRM and no comments were received on 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.

Cost Impact
The FAA estimates that 350 airplanes in the U.S. registry will be affected by the initial replacement, that it will take approximately 4 workhours per airplane to accomplish this action, and that the average labor rate is approximately $60 an hour. Parts cost approximately $2,500 per airplane. Based on these figures, the total cost impact of the initial replacement on U.S. operators is estimated to be $959,000, or $2,740 per airplane.

These figures only take into account the cost of the initial overhaul or replacement and do not take into account the cost of subsequent overhauls or replacements. The FAA has no way of determining the number of overhauls or replacements that each owner/operator of the affected airplanes will incur over the life of his/her airplane.

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 Part39
Air transportation, Aircraft, Aviation 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: