Airworthiness directives: British Aerospace,

[Federal Register: July 7, 1998 (Volume 63, Number 129)]

[Proposed Rules]

[Page 36630-36632]

From the Federal Register Online via GPO Access [wais.access.gpo.gov]

[DOCID:fr07jy98-22]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-167-AD]

RIN 2120-AA64

Airworthiness Directives; British Aerospace (Jetstream) Model 4101 Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

SUMMARY: This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain British Aerospace (Jetstream) Model 4101 airplanes. This proposal would require modification of the attach points of the uplock system of the nose landing gear (NLG). This proposal is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by the proposed AD are intended to prevent wear of the attach points of the uplock system of the NLG; such wear could result in damage to the adjacent emergency hydraulic system, or jamming of the uplock system and consequent inability to extend and retract the NLG.

DATES: Comments must be received by August 6, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 98-NM-167-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except Federal holidays.

The service information referenced in the proposed rule may be obtained from AI(R) American Support , Inc., 13850 Mclearen Road, Herndon, Virginia 20171. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT: Norman B. Martenson, Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-2110; fax (425) 227-1149.

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SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the proposed rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this notice may be changed in light of the comments received.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report summarizing each FAA-public contact concerned with the substance of this proposal will be filedin the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this notice must submit a self-addressed, stamped postcard on which the following statement is made: ``Comments to Docket Number 98-NM-167-AD.'' The postcard will be date stamped and returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 98-NM-167-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

The Civil Aviation Authority (CAA), which is the airworthiness authority for the United Kingdom, notified the FAA that an unsafe condition may exist on certain British Aerospace (Jetstream) Model 4101 airplanes. The CAA advises that it has received reports of wear of the attach points of the uplock system of the nose landing gear (NLG). Investigation revealed that the wear is due to excessive loads from the uplock system, which caused excessive movement of the uplock mechanisms. Such wear of the attach points of the NLG uplock system, if not corrected, could result in damage to the adjacent emergency hydraulic system, or jamming of the uplock system and consequent inability to extend and retract the NLG.

Explanation of Relevant Service Information

The manufacturer has issued Jetstream Alert Service Bulletin J41- 53-041, dated July 25, 1997, which describes procedures for modification of the attach points of the uplock system of the NLG. The modification involves installation of nested angle stiffeners on the ``Z'' members near the NLG and removal and replacement of the distance tubes and pieces with new distance tubes and pieces. Accomplishment of the actions specified in the alert service bulletin is intended to adequately address the identified unsafe condition. The CAA classified this alert service bulletin as mandatory and issued British airworthiness directive 009-07-97 in order to assure the continued airworthiness of these airplanes in the United Kingdom.

FAA's Conclusions

This airplane model is manufactured in the United Kingdom and is type certificated for operation in the United States under the provisions of Sec. 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral airworthiness agreement. Pursuant to this bilateral airworthiness agreement, the CAA has kept the FAA informed of the situation described above. The FAA has examined the findings of the CAA, reviewed all available information, and determined that AD action is necessary for products of this type design that are certificated for operation in the United States.

Explanation of Requirements of Proposed Rule

Since an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design registered in the United States, the proposed AD would require accomplishment of the actions specified in the alert service bulletin described previously.

Cost Impact

The FAA estimates that 58 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 10 work hours per airplane to accomplish the proposed modification, and that the average labor rate is $60 per work hour. Required parts would cost approximately $170 per airplane. Based on these figures, the cost impact of the proposed AD on U.S. operators is estimated to be $44,660, or $770 per airplane.

The cost impact figure discussed above is based on assumptions that no operator has yet accomplished any of the proposed requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted.

Regulatory Impact

The regulations proposed herein would 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 proposal would not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.

For the reasons discussed above, I certify that 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) if promulgated, 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 draft regulatory 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, Safety.

The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 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.

   Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding the following new airworthiness directive:

   British Aerospace Regional Aircraft [Formerly Jetstream Aircraft Limited; British Aerospace (Commercial Aircraft) Limited]: Docket 98-NM-167-AD.

   Applicability: Jetstream Model 4101 airplanes, constructor's numbers 41004 through 41100 inclusive; certificated in any category.

   Note 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been

   [[Page 36632]]

   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 (b) 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 wear of the attach points of the uplock system of the nose landing gear (NLG), which could result in damage to the adjacent emergency hydraulic system, or jamming of the uplock system, and consequent inability to extend and retract the NLG, accomplish the following:

   (a) Prior to the accumulation of 9,000 total landings, or within 1,000 landings after the effective date of this AD, whichever occurs later, modify the attach points of the uplock system of the NLG, in accordance with Jetstream Alert Service Bulletin J41-53-041, dated July 25, 1997.

   (b) 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, International Branch, ANM-116, 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, International Branch, ANM-116.

   Note 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the International Branch, ANM-116.

   (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.

   Note 3: The subject of this AD is addressed in British airworthiness directive 009-07-97.

   Issued in Renton, Washington, on June 30, 1998. Vi L. Lipski, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

   [FR Doc. 98-17950Filed7-6-98; 8:45 am]

   BILLING CODE 4910-13-U