Airworthiness Directives; BAE Systems (Operations) Limited (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 all BAE Systems (Operations) Limited (Jetstream) Model 4101 airplanes. This proposal would require a test for free movement of the capsule/bearing of the nose landing gear (NLG), and related investigative, significant, and corrective actions. This action is necessary to prevent failure of the NLG to extend fully, which could result in reduced controllability of the airplane during landing. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by June 11, 2004.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2004-NM-46-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9 a.m. and 3 p.m., Monday through Friday, except Federal holidays. Comments may be submitted via fax to (425) 227-1232. Comments may also be sent via the Internet using the following address: 9-anm-nprmcomment@faa.gov. Comments sent via fax or the Internet must contain “Docket No. 2004-NM-46-AD” in the subject line and need not be submitted in triplicate. Comments sent via the Internet as attached electronic files must be formatted in Microsoft Word 97 or 2000 or ASCII text.

The service information referenced in the proposed rule may be obtained from British Aerospace Regional Aircraft American Support, 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:

Todd Thompson, Aerospace Engineer, International Branch, ANM-116, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-1175; fax (425) 227-1149.

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 action may be changed in light of the comments received.

Submit comments using the following format:

• Organize comments issue-by-issue. For example, discuss a request to change the compliance time and a request to change the service bulletin reference as two separate issues.
• For each issue, state what specific change to the proposed AD is being requested.
• Include justification (e.g., reasons or data) for each request.

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 filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this action must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 2004-NM-46-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. 2004-NM-46-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 all BAE Systems (Operations) Limited (Jetstream) Model 4101 airplanes. The CAA advises that there have been several incidents in which the nose landing gear (NLG) did not fully extend, necessitating an emergency landing. Investigation suggests that the cause may be related to binding between the upper and lower sliding/support bearings and the NLG capsule that is part of the shortening mechanism. High friction at the upper bearing or lower bearing may prevent free movement of the NLG capsule. This condition, if not corrected, could result in failure of the NLG to extend fully, and consequent reduced controllability of the airplane during landing.

Explanation of Relevant Service Information

BAE Systems (Operations) Limited has issued Alert Service Bulletin J41-A32-082, Revision 1, dated February 20, 2004. That service bulletin describes procedures for a test for free movement of the NLG capsule/bearing, and related investigative, significant, and corrective actions. These actions are described below.

The BAE Systems service bulletin refers to APPH Service Bulletin AIR83586-32-22, Revision 1, dated February 2004, as an additional source of service information. Paragraph 2.A. (Part 1) of that service bulletin describes procedures for the initial test for free movement of the NLG capsule. Paragraph 2.B. (Part 2) of that service bulletin describes procedures for related investigative, significant, and corrective actions following the initial test. These related investigative, significant, and corrective actions entail cleaning and re-greasing the bearings, and repeating the test for free movement (i.e., Part 1 of the APPH service bulletin). If the test immediately following the cleaning and re-greasing of bearings fails, corrective actions entail repairing or replacing the NLG.

If the NLG capsule/bearing moves freely during the initial test, the BAE Systems service bulletin specifies a compliance time of 3,000 flight hours for the related investigative, significant, and corrective actions (Parts 1 and 2 of the APPH service bulletin). If the movement of the NLG capsule/bearing is restricted during the initial test, the BAE Systems service bulletin specifies that the related investigative and corrective actions (Parts 1 and 2 of the APPH service bulletin) must be done before further flight. If the capsule moves freely during the test immediately following accomplishment of Part 2, the BAE Systems service bulletin specifies repeating the test within 600 flight hours.

Accomplishment of the actions specified in the service bulletins is intended to adequately address the identified unsafe condition. The CAA classified the service bulletins as mandatory and issued British emergency airworthiness directive G-2004-0003, dated February 24, 2004, to ensure 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 section 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 us informed of the situation described above. We have 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 BAE Systems service bulletin described previously, except as discussed below.

Differences Between Proposed AD and Service Bulletins

Although the service bulletins specify that operators may contact BAE Systems or APPH for disposition of certain repair conditions, this proposal would require operators to repair those conditions per a method approved by either the FAA or the CAA (or its delegated agent). In light of the type of repair that would be required to address the unsafe condition, and consistent with existing bilateral airworthiness agreements, we have determined that, for this proposed AD, a repair approved by either the FAA or the CAA would be acceptable for compliance with this proposed AD.

This proposed AD refers to the flow chart in the BAE Systems service bulletin for compliance times for certain actions. The flow chart does not clearly state a compliance time for applicable corrective actions if the movement of the NLG capsule/bearing is restricted during any test. Therefore, paragraph (c) of this AD specifies that, if the movement of the NLG capsule/bearing is restricted during any test, the applicable corrective actions must be accomplished before further flight.

For compliance times, the flow chart in the BAE Systems service bulletin specifies a certain number of “flying hours.” Paragraph (c) of this proposed AD specifies performing the actions at the compliance times in the flow chart of the BAE Systems service bulletin. However, where the flow chart specifies “flying hours,” the definition in this proposed AD would be “flight hours.” This decision is based on our determination that “flying hours” may be interpreted differently by different operators. We find that our proposed terminology is generally understood within the industry.

Although the Accomplishment Instructions of the BAE Systems service bulletin describe procedures for submitting a form reporting inspection results to the manufacturer, this proposed AD would not require those actions.

Cost Impact

We estimate that 57 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 6 work hours per airplane to accomplish the proposed actions, and that the average labor rate is $65 per work hour. Based on these figures, the cost impact of the proposed AD on U.S. operators is estimated to be $22,230, or $390 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. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions.

Regulatory Impact

The regulations proposed herein 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. Therefore, it is determined that this proposal would not have federalism implications under Executive Order 13132.

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.