AD 2008-12-02

We are adopting a new airworthiness directive (AD) for the products listed above. This AD results from mandatory continuing airworthiness information (MCAI) issued by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as:

A failure mode has been identified following the examination of parts from another aircraft type (Jetstream 4100 series) that can lead to the loss of a nose-wheel. The Jetstream (HP.137) Mk1, 200, 3100 and 3200 series use a similar method for retaining the wheel assemblies on the landing gear axle and can therefore experience the same type of failure, i.e. a combination of excessive wear and/or adverse tolerances on the axle inner cone, outer cone or wheel hub splined sleeve cones resulting in the loss of the critical gap between the inner flange face of the wheel outer cone and the axle end face. If this gap is lost, it results in the wheel having free playalong the length of the axle. This condition, if not corrected, can cause the wheel nut lock plate to break, leading to the wheel retention nut unscrewing and subsequent separation of the nose wheel from the landing gear axle.

We are issuing this AD to require actions to correct the unsafe condition on these products.

Final Rule.

2008-12-02 British Aerospace Regional Aircraft: Amendment 39-15545; Docket No. FAA-2008-0369; Directorate Identifier 2008-CE-015-AD.

Effective Date

(a) This airworthiness directive (AD) becomes effective July 16, 2008.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Model HP.137 Jetstream Mk.1, Jetstream Series 200 and 3101, and Jetstream Model 3201 airplanes, all serial numbers, certificated in any category.

Subject

(d) Air Transport Association of America (ATA) Code 32: Landing Gear.

Reason

(e) The mandatory continuing airworthiness information (MCAI) states:

A failure mode has been identified following the examination of parts from another aircraft type (Jetstream 4100 series) that can lead to the loss of a nose-wheel. The Jetstream (HP.137) Mk1, 200, 3100 and 3200 series use a similar method for retaining the wheel assemblies on the landing gear axle and can therefore experience the same type of failure, i.e. a combination of excessive wear and/or adverse tolerances on the axle inner cone, outer cone or wheel hub splined sleeve cones resulting in the loss of the critical gap between the inner flange face of the wheel outer cone and the axle end face. If this gap is lost, it results in the wheel having free play along the length of the axle. This condition, if not corrected, can cause the wheel nut lock plate to break, leading to the wheel retention nut unscrewing and subsequent separation of the nose wheel from the landing gear axle.

For the reasons described above, this AD requires repetitive inspections of the nose landing gear to ensure that the wheels are correctly retained and, depending on findings, replacement of worn parts.

Actions and Compliance

(f) Unless already done, do the following actions:

(1) Within the next 3 months after July 16, 2008 (the effective date of this AD), initially inspect the left and right nose wheel attachments to the axle following British Aerospace Jetstream Series 3100 and 3200 Service Bulletin 32-JA070241, dated July 13, 2007.

(2) Repetitively thereafter inspect the left and right nose wheel attachments to the axle at the intervals specified in Table 1 of this AD following British Aerospace Jetstream Series 3100 and 3200 Service Bulletin 32-JA070241, dated July 13, 2007. If during any repetitive inspection the gap measurement changes from the previous inspection measurement, adjust the repetitive inspection interval as necessary based on Table 1 of this AD.

Table 1.--Repetitive Inspection Intervals

If the Measured Gap Size is:
Then repetitively inspect at the following intervals:
0.002 through 0.005 inches (0.05 through 0.13 mm)
Within 500 hours time-in-service (TIS)
More than 0.005 through 0.010 inches (0.13 through 0.25 mm)
Within 1,000 hours TIS
More than 0.010 through 0.020 inches (0.25 through 0.51 mm)
Within 2,000 hours TIS
More than 0.020 inches (0.51 mm)
Within 3,000 hours TIS

(3) Before further flight, if during any of the inspections required in paragraphs (f)(1) or (f)(2) of this AD you find the gap between the inner flange of the outer cone and the axle end face is less than 0.002 inches (0.05 mm), replace all worn parts.

Note 1: Replacement of parts does not constitute terminating action for the inspection requirements of this AD.

FAA AD Differences

Note 2: This AD differs from the MCAI and/or service information as follows: No differences.

Other FAA AD Provisions

(g) The following provisions also apply to this AD:

(1) Alternative Methods of Compliance (AMOCs): The Manager, Standards Office, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Send information to ATTN: Taylor Martin, Aerospace Engineer, FAA, Small Airplane Directorate, 901 Locust, Room 301, Kansas City, Missouri 64106; telephone: (816) 329-4138; fax: (816) 329-4090. Before using any approved AMOC on any airplane to which the AMOC applies, notify your appropriate principal inspector (PI) in the FAA Flight Standards District Office (FSDO), or lacking a PI, your local FSDO.

(2) Airworthy Product: For any requirement in this AD to obtain corrective actions from a manufacturer or other source, use these actions if they are FAA-approved. Corrective actions are considered FAA-approved if they are approved by the State of Design Authority (or their delegated agent). You are required to assure the product is airworthy before it is returned to service.

(3) Reporting Requirements: For any reporting requirement in this AD, under the provisions of the Paperwork Reduction Act (44 U.S.C. 3501 et seq.), the Office of Management and Budget (OMB) has approved the information collection requirements and has assigned OMB Control Number 2120-0056.

Related Information

(h) Refer to MCAI European Aviation Safety Agency (EASA) AD No: 2008-0037, dated February 22, 2008; and British Aerospace Jetstream Series 3100 and 3200 Service Bulletin 32-JA070241, dated July 13, 2007, for related information.

Material Incorporated by Reference

(i) You must use British Aerospace Jetstream Series 3100 and 3200 Service Bulletin 32-JA070241, dated July 13, 2007, to do the actions required by this AD, unless the AD specifies otherwise.

(1) The Director of the Federal Register approved the incorporation by reference of this service information under 5 U.S.C. 552(a) and 1 CFR part 51.

(2) For service information identified in this AD, contact Project Management Group, Customer Information Department, BAE SYSTEMS (OPERATIONS), Prestwick International Airport, Ayrshire, KA9 2RW, Scotland; telephone: +44 1292 675207; fax: +44 1292 675704; e- mail: RApublications@baesystems.com.

(3) You may review copies at the FAA, Central Region, Office of the Regional Counsel, 901 Locust, Room 506, Kansas City, Missouri 64106; or at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal- register/cfr/ibr-locations.html.

Discussion

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an AD that would apply to the specified products. That NPRM was published in the Federal Register on March 31, 2008 (73 FR 16790). That NPRM proposed to correct an unsafe condition for the specified products. The MCAI states:

A failure mode has been identified following the examination of parts from another aircraft type (Jetstream 4100 series) that can lead to the loss of a nose-wheel. The Jetstream (HP.137) Mk1, 200, 3100 and 3200 series use a similar method for retaining the wheel assemblies on the landing gear axle and can therefore experience the same type of failure, i.e. a combination of excessive wear and/or adverse tolerances on the axle inner cone, outer cone or wheel hub splined sleeve cones resulting in the loss of the critical gap between the inner flange face of the wheel outer cone and the axle end face. If this gap is lost, it results inthe wheel having free play along the length of the axle. This condition, if not corrected, can cause the wheel nut lock plate to break, leading to the wheel retention nut unscrewing and subsequent separation of the nose wheel from the landing gear axle.

For the reasons described above, this AD requires repetitive inspections of the nose landing gear to ensure that the wheels are correctly retained and, depending on findings, replacement of worn parts.

You may obtain further information by examining the MCAI in the AD docket.

Comments

We gave the public the opportunity to participate in developing this AD. We received no comments on the NPRM or on the determination of the cost to the public.

Conclusion

We reviewed the available data and determined that air safety and the public interest require adopting the AD as proposed.

Differences Between This AD and the MCAI or Service Information

We have reviewed the MCAI and related service information and, ingeneral, agree with their substance. But we might have found it necessary to use different words from those in the MCAI to ensure the AD is clear for U.S. operators and is enforceable. In making these changes, we do not intend to differ substantively from the information provided in the MCAI and related service information.

We might also have required different actions in this AD from those in the MCAI in order to follow FAA policies. Any such differences are highlighted in a NOTE within the AD.

Costs of Compliance

Based on the service information, we estimate that this AD will affect 190 products of U.S. registry. We also estimate that it will take about 1 work-hour per product to comply with basic requirements of this AD. The average labor rate is $80 per work-hour.

Based on these figures, we estimate the cost of this AD to the U.S. operators to be $15,200 or $80 per product.

In addition, we estimate that any necessary follow-on actions would take about 1 work-hour and require parts costing $250, for a cost of $330 per product. We have no way of determining the number of products that may need these actions.

Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. "Subtitle VII: Aviation Programs," describes in more detail the scope of the Agency's authority.

We are issuing this rulemaking under the authority described in "Subtitle VII, Part A, Subpart III, Section 44701: General requirements." Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in thisrulemaking action.

Regulatory Findings

We determined that this AD will not have federalism implications under Executive Order 13132. This AD will not have a substantial direct effect 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.

For the reasons discussed above, I certify this AD:

(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.

We prepared a regulatory evaluation of the estimated costs to comply with this AD and placed it in the AD Docket.

Examining the AD Docket

You may examine the AD docket on the Internet at http:// www.regulations.gov; or in person at the Docket Management Facility between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains the NPRM, the regulatory evaluation, any comments received, and other information. The street address for the Docket Office (telephone (800) 647-5527) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.

Adoption of the Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA amends 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. The FAA amends Sec. 39.13 by adding the following new AD: