04-50. Airworthiness Directives; BAE Systems (Operations) Limited Model Avro 146-RJ Series Airplanes; and BAE Systems (Operations) Limited Model BAe 146 Series 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 BAE Systems (Operations) Limited Model Avro 146-RJ and Model BAe 146 series airplanes. This proposal would require a test to determine the torque setting for the collar cap screw of the differential box for the nose landing gear, and follow-on actions. This action is necessary to prevent uncommanded inputs to the nosewheel steering, which could result in reduced controllability of the airplane during takeoff and landing. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by February 4, 2004.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2001-NM-317-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 [phone]. Comments may also be sent via the Internet using the following address: [e-mail]. Comments sent via fax or the Internet must contain “Docket No. 2001-NM-317-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 [phone]; fax [phone].

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 2001-NM-317-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. 2001-NM-317-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 BAE Systems (Operations) Limited Model Avro 146-RJ and Model BAe 146 series airplanes. The CAA advises that there have been twenty incidents of uncommanded inputs to the nosewheel steering. These incidents involved five different nose landing gears and six different airplanes. Investigation determined that, on all the gears involved in incidents, the torque setting for the collar cap screw of the differential box was significantly lower than the original design standard. This condition, if not corrected, could lead to uncommanded inputs to the nosewheel steering, which could result in reduced controllability of the airplane during takeoff and landing.

Explanation of Relevant Service Information

BAE Systems (Operations) Limited has issued Service Bulletin ISB.32-168, dated August 6, 2001, which describes procedures for a check to determine the torque setting for the collar cap screw of the differential box, and follow-on actions. The follow-on actions involve torquing the collar cap screw to a specified limit and performing a functional test of the nosewheel. Accomplishment of the actions specified in the service bulletin is intended to adequately address the identified unsafe condition. The CAA classified this service bulletin as mandatory and issued British Airworthiness Directive 004-08-2001, to ensure the continued airworthiness of these airplanes in the United Kingdom.

BAE Systems (Operations) Limited Service Bulletin ISB.32-168 references Messier-Dowty Service Bulletin 146-32-154, dated August 3, 2001, as an additional source of service information for accomplishment of the detailed inspection and follow-on actions.

FAA's Conclusions

These airplane models are manufactured in the United Kingdom and are 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 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 service bulletin described previously, except as discussed below.

Difference Between the Proposed AD and the Messier-Dowty Service Bulletin

Although the Messier-Dowty service bulletin specifies to report inspection results to the manufacturer, this proposed AD does not require that action.

Difference Between the Proposed AD and the BAE Service Bulletin

Although the BAE service bulletin specifies that operators may contact the manufacturer for disposition if the steering mechanism will not return to the neutral position following a functional test, this proposed AD would require operators to repair this condition 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.

Cost Impact

The FAA estimates that 55 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 2 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 $7,150, or $130 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.

§ 39.13

[Amended]

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

Bae Systems (Operations) Limited (Formerly British Aerospace Regional Aircraft): Docket 2001-NM-317-AD.

Applicability: Model Avro 146-RJ series airplanes; and Model BAe 146 series airplanes; equipped with a nose landing gear having a part number listed under paragraph 1.A.(1) of BAE Systems (Operations) Limited Service Bulletin ISB.32-168, dated August 6, 2001; certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent uncommanded inputs to the nosewheel steering, which could result in reduced controllability of the airplane during takeoff and landing, accomplish the following:

Note 1:

BAE Systems (Operations) Limited Service Bulletin ISB.32-168, dated August 6, 2001, references Messier-Dowty Service Bulletin 146-32-154, dated August 3, 2001, as an additional source of service information for accomplishment of the detailed inspection and follow-on actions. Although the Messier-Dowty service bulletin specifies to submit certain information to the manufacturer, this AD does not include such a requirement.

Torque Test and Follow-on Actions

(a) Within 6 months after the effective date of this AD: Perform a torque test of the collar cap screw of the differential box for the nose landing gear, and do all applicable follow-on actions before further flight in accordance with the Accomplishment Instructions of BAE Systems (Operations) Limited Service Bulletin ISB.32-168, dated August 6, 2001.

(b) If the steering mechanism will not return to the neutral position following the functional test in paragraph 2.C. of the Accomplishment Instructions of BAE Systems (Operations) Limited Service Bulletin ISB.32-168, dated August 6, 2001, before further flight: Repair per a method approved by either the Manager, International Branch, ANM-116, FAA, Transport Airplane Directorate; or the CAA (or its delegated agent).

Parts Installation

(c) As of the effective date of this AD, no person may install on any airplane a nose landing gear assembly unless the torque test and follow-on actions have been accomplished in accordance with the paragraph 2.B. of BAE Systems (Operations) Limited Service Bulletin ISB.32-168, dated August 6, 2001.

Alternative Methods of Compliance

(d) In accordance with 14 CFR 39.19, the Manager, International Branch, FAA, Transport Airplane Directorate, is authorized to approve alternative methods of compliance for this AD.

Note 2:

The subject of this AD is addressed in British airworthiness directive 004-08-2001.

Issued in Renton, Washington, on December 29, 2003.

Ali Bahrami,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.