04-4048. 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 review of airplane maintenance records and an inspection of the nose landing gear (NLG) to determine the part number of the steering pinion, and follow-on/corrective actions as applicable. The actions specified by the proposed AD are intended to prevent failure of the steering pinion in the NLG, which could result in loss of steering and possible damage to the airplane during takeoff and landing. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by March 26, 2004.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2001-NM-288-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-288-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-288-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-288-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 the manufacturer of the landing gear reported that a batch of steering pinions installed in the nose landing gear (NLG) were incorrectly heat treated, resulting in a softer base metal and reduced fatigue life. A steering pinion with reduced strength can affect the structural integrity of the NLG. This condition, if not corrected, could result in failure of the steering pinion in the NLG, and consequent loss of steering and possible damage to the airplane during takeoff and landing.

Explanation of Relevant Service Information

BAE Systems (Operations) Limited has issued Service Bulletin J41-32-076, dated July 3, 2001, which reduces the life limit of the steering pinion from 60,000 cycles to 12,000 cycles. Part 1 of the Accomplishment Instructions of the service bulletin describes procedures for identification of the part number for the steering pinion located in the NLG, including a review of airplane maintenance records and an inspection of the NLG to identify the part number, gear overhaul status, and total cycles since new and since overhaul; and establishing the replacement threshold for the steering pinion. For certain airplanes, the procedures include temporarily installing a placard in the flight deck prohibiting powered pushbacks. Also for certain airplanes, Part 2 of the Accomplishment Instructions of the service bulletin describes procedures of replacing the NLG with a serviceable NLG, and a functional test.

BAE Systems (Operations) Limited has also issued Service Bulletin J41-32-077, dated August 31, 2001, which includes procedures for installing a NLG having a new, improved steering pinion with a life limit of 60,000 landings; and a functional test of the landing gear. Accomplishment of this service bulletin restores the life limit of the steering pinion to 60,000 landings.

Accomplishment of the actions specified in these service bulletins is intended to adequately address the identified unsafe condition. The CAA classified Service Bulletin J41-32-076 as mandatory and issued British airworthiness directive 001-07-2001 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 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 AD

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 bulletins described previously, except as discussed below.

Clarification of Terminology and Applicability

BAE Systems (Operations) Limited Service Bulletin J41-32-076 refers to the number of “cycles” on the NLG. Service Bulletin J41-32-077 refers to the number of “landings” on the NLG. For consistency we use the term “landings” throughout the body of this proposed AD.

The effectivity in the service bulletins and the applicability of the British airworthiness directive reference “all series 4100 aircraft.” Of the series 4100 airplanes, only Model Jetstream 4101 has been type certificated in the United States. The applicability for this proposed AD is all Model Jetstream 4101 airplanes.

Difference Among the Proposed AD, British Airworthiness Directive, and Service Bulletins

Part 1 of the Accomplishment Instructions of BAE Systems (Operations) Limited Service Bulletin J41-32-076 refers to steering pinion part number (P/N) AIR131714. BAE states that this part is acceptable as a serviceable replacement part for the existing steering pinion and was included in the service bulletin to remind operators that it has a fatigue life of 19,000 cycles instead of 12,000 cycles. This part number is not referenced in the British airworthiness directive, but a paragraph referencing this part has been included in this proposed AD. This difference has been coordinated with the CAA.

The service bulletins referenced in this proposed AD specify to notify the manufacturer when the actions in the service bulletins have been accomplished; however, this proposed AD does not include such a requirement.

Cost Impact

The FAA estimates that 57 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 14 work hours per airplane to accomplish the proposed identification of the P/N for the steering pinion in Part 1 of BAE Systems (Operations) Limited Service Bulletin J41-32-076, and that the average labor rate is $65 per work hour. The cost for a temporary placard, if required, would be minimal. Based on these figures, the cost impact of the proposed P/N identification is estimated to be $51,870, or $910 per airplane.

Should an operator be required to replace a steering pinion per Part 2 of BAE Systems (Operations) Limited Service Bulletin J41-32-076, it would take approximately 16 work hours per airplane, at an average labor rate of $65 per work hour. The manufacturer of the NLG would provide parts to affected operators at no cost. Based on these figures, the cost impact of the replacement is estimated to be $1,040 per airplane.

The cost impact figures discussed above are 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-288-AD.

Applicability: All Model Jetstream 4101 airplanes, certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent failure of the steering pinion in the nose landing gear (NLG), which could result in a loss of steering and possible damage to the airplane during takeoff and landing, accomplish the following:

Identification of Steering Pinion Part Number and Follow-on/Corrective Actions

(a) Within 60 days after the effective date of this AD: Do a review of the airplane maintenance records and a general visual inspection of the NLG to identify the part number (P/N) of the steering pinion, and to determine the total cycles since new and since overhaul of the NLG, by accomplishing all of the applicable actions in accordance with Part 1 of the Accomplishment Instructions of BAE Systems (Operations) Limited Service Bulletin J41-32-076, dated July 3, 2001.

Note 1:

For the purposes of this AD, a general visual inspection is defined as: “A visual examination of an interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. This level of inspection is made from within touching distance unless otherwise specified. A mirror may be necessary to enhance visual access to all exposed surfaces in the inspection area. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or droplight and may require removal or opening of access panels or doors. Stands, ladders, or platforms may be required to gain proximity to the area being checked.”

(b) If the steering pinion P/N is identified as AIR136088, and the NLG has more than 12,000 total landings since new or overhaul: Before further flight, after accomplishing the actions required by paragraph (a) of this AD, install a temporary placard prohibiting pushback with engines running in accordance with Part 1 of the Accomplishment Instructions of BAE Systems (Operations) Limited Service Bulletin J41-32-076, dated July 3, 2001.

(c) Based on the criteria in the Accomplishment Instructions of BAE Systems (Operations) Limited Service Bulletin J41-32-076, dated July 3, 2001, if it is determined that the NLG must be replaced with a serviceable NLG, accomplish the replacement in accordance with the Accomplishment Instructions of the service bulletin. Do the replacement at the later of the times specified in paragraphs (c)(i) and (c)(ii) of this AD. After replacement of an existing NLG the temporary placard required by paragraph (b) of this AD may be removed from the airplane.

(i) Prior to the accumulation of 12,000 total landings on the NLG since new or overhaul.

(ii) Within 1,000 landings or 16 months after the effective date of this AD, whichever occurs first.

Repetitive Replacement

(d) After the initial replacement of a NLG as required by paragraph (c) of this AD: Replace the NLG with a serviceable NLG thereafter at intervals not to exceed 12,000 landings on the NLG, until accomplishment of paragraph (f) of this AD.

(e) If P/N AIR131714 is installed on the airplane, or if an operator installs this P/N as a serviceable replacement part, this part must be replaced at or before the accumulation of 19,000 total landings on the part, and thereafter at intervals not to exceed 19,000 total landings on the part, until accomplishment of paragraph (f) of this AD.

(f) Replacement of a NLG with a new NLG having P/N AIR83586-18, or any P/N AIR83586-xx (where xx represents the “dash” number of the part) with “mod 19 strike-off” recorded on the nameplate, in accordance with the Accomplishment Instructions of BAE Systems (Operations) Limited Service Bulletin J41-32-077, dated August 31, 2001, restores the life limits of the steering pinion to 60,000 landings on the NLG. Replace the NLG thereafter at intervals not to exceed 60,000 landings on the NLG.

Submission of Information to Manufacturer Not Required

(g) Although the service bulletins referenced in this AD specify to notify the manufacturer when the actions in the service bulletins have been accomplished, this AD does not include such a requirement.

Alternative Methods of Compliance

(h) In accordance with 14 CFR 39.19, the Manager, International Branch, ANM-116, Transport Airplane Directorate, FAA, is authorized to approve alternative methods of compliance for this AD.

Note 2:

The subject of this AD is addressed in British airworthiness directive 001-07-2001.

Issued in Renton, Washington, on February 17, 2004.

Ali Bahrami,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.