Airworthiness Directives; British Aerospace Regional Aircraft ModelHP. 137 Jetstream MK 1, Jetstream Series 200, 3100, and 3200 Airplanes

Summary:

We propose to adopt a new airworthiness directive (AD) for the products listed above. This proposed AD results from mandatory continuing airworthiness information (MCAI) originated 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 200 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.

The proposed AD would require actions that are intended to address the unsafe condition described in the MCAI.

Table of Contents

Table of Figures

Addresses:

You may send comments by any of the following methods:

• Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.

• Fax: (202) 493-2251.

• Mail: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590.

• Hand Delivery: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

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 this proposed AD, 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.

For further information contact:

Taylor Martin, Aerospace Engineer, FAA, Small Airplane Directorate, 901 Locust, Room 301, Kansas City, Missouri 64106; telephone: (816) 329-4138; fax: (816) 329-4090.

Supplementary information:

Comments Invited

We invite you to send any written relevant data, views, or arguments about this proposed AD. Send your comments to an address listed under the ADDRESSES section. Include “Docket No. FAA-2008-0369; Directorate Identifier 2008-CE-015-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this proposed AD. We will consider all comments received by the closing date and may amend this proposed AD because of those comments.

We will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this proposed AD.

Discussion

The European Aviation Safety Agency (EASA), which is the Technical Agent for the Member States of the European Community, has issued AD No: 2008-0037, dated February 22, 2008 (referred to after this as “the MCAI”), 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 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.

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

Relevant Service Information

British Aerospace Regional Aircraft has issued British Aerospace Jetstream Series 3100 and 3200 Service Bulletin 32-JA070241, dated July 13, 2007. The actions described in this service information are intended to correct the unsafe condition identified in the MCAI.

FAA's Determination and Requirements of the Proposed AD

This product has been approved by the aviation authority of another country, and is approved for operation in the United States. Pursuant to our bilateral agreement with this State of Design Authority, they have notified us of the unsafe condition described in the MCAI and service information referenced above. We are proposing this AD because we evaluated all information and determined the unsafe condition exists and is likely to exist or develop on other products of the same type design.

Differences Between This Proposed AD and the MCAI or Service Information

We have reviewed the MCAI and related service information and, in general, 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 proposed 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 proposed AD.

Costs of Compliance

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

Based on these figures, we estimate the cost of the proposed AD on 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 this rulemaking action.

Regulatory Findings

We determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would 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 proposed regulation:

1. Is not a “significant regulatory action” under Executive Order 12866;

2. Is not a “significant rule” under the 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 proposed AD and placed it in the AD docket.

List of subjects in 14 cfr part 39

Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 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

2. The FAA amends § 39.13 by adding the following new AD:

British Aerospace Regional Aircraft: Docket No. FAA-2008-0369; Directorate Identifier 2008-CE-015-AD.

Comments Due Date

(a) We must receive comments by April 30, 2008.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Model HP. 137 Jetstream MK 1, Jetstream Series 200, 3100, and 3200 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 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 to 0.005 inches (0.05 to 0.13 mm) Within 500 hours TIS.
More than 0.005 to 0.010 inches (0.13 to 0.25 mm) Within 1,000 hours TIS.
More than 0.010 to 0.020 inches (0.25 to 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 theseactions 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.

Issued in Kansas City, Missouri, on March 21, 2008. David R. Showers,

Acting Manager, Small Airplane Directorate, Aircraft Certification Service.

References

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