Airworthiness Directives; British Aerospace HP137 Mk1, Jetstream Series 200, and Jetstream Models 3101 and 3201 Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes to adopt a new airworthiness directive (AD) that would apply to certain British Aerospace HP137 Mk1, Jetstream series 200, and Jetstream Models 3101 and 3201 airplanes that are equipped with certain nose landing gear units. The proposed AD would require you to inspect the steering jack assembly to assure proper clearance between the bush heads on the steering plates and the shim on the steering jack trunnions and to assure that there is adequate lubrication at both trunnions and the eye end fitting. The proposed AD would also require you to adjust the clearance and provide adequate lubrication, as necessary. The proposed AD is the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for the United Kingdom. The actions specified by the proposed AD are intended to prevent cracked steering jack piston rods caused by inadequate clearance or inadequate lubrication of the steering jack pivot points. The condition could result in failure of the nose wheel steering system with consequent loss of airplane control.

DATES:

The Federal Aviation Administration (FAA) must receive any comments on this proposed rule on or before November 22, 2000.

ADDRESSES:

Submit comments in triplicate to FAA, Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 99-CE-83-AD, 901 Locust, Room 506, Kansas City, Missouri 64106. Comments may be inspected at this location between 8 a.m. and 4 p.m., Monday through Friday, holidays excepted.

Service information that applies to the proposed AD may be obtained from British Aerospace Regional Aircraft, Prestwick International Airport, Ayrshire, KA9 2RW, Scotland; telephone: (01292) 479888; facsimile: (01292) 479703. This information also may be examined at the Rules Docket at the address above.

FOR FURTHER INFORMATION CONTACT:

Mr. S.M. Nagarajan, Aerospace Engineer, FAA, Small Airplane Directorate, 901 Locust, Room 301, Kansas City, Missouri 64106; telephone: (816) 329-4145; facsimile: (816) 329-4090.

SUPPLEMENTARY INFORMATION:

Comments Invited

How do I comment on the proposed AD? The FAA invites comments on this proposed rule. You may submit whatever written data, views, or arguments you choose. You need to include the rule's docket number and submit your comments in triplicate to the address specified under the caption ADDRESSES. The FAA will consider all comments received on or before the closing date. We may amend the proposed rule in light of comments received. Factual information that supports your ideas and suggestions is extremely helpful in evaluating the effectiveness of the proposed AD action and determining whether we need to take additional rulemaking action.

Are there any specific portions of the proposed AD I should pay attention to? The FAA specifically invites comments on the overall regulatory, economic, environmental, and energy aspects of the proposed rule that might suggest a need to modify the rule. You may examine all comments we receive before and after the closing date of the rule in the Rules Docket. We will file a report in the Rules Docket that summarizes each FAA contact with the public that concerns the substantive parts of the proposed AD.

We are re-examining the writing style we currently use in regulatory documents, in response to the Presidential memorandum of June 1, 1998. That memorandum requires Federal agencies to communicate more clearly with the public. We are interested in your comments on whether the style of this document is clearer, and any other suggestions you might have to improve the clarity of FAA communications that affect you. You can get more information about the Presidential memorandum and the plain language initiative at http://www.plainlanguage.gov.

How can I be sure FAA receives my comment? If you want us to acknowledge the receipt of your comments, you must include a self-addressed, stamped postcard. On the postcard, write “Comments to Docket No. 99-CE-83-AD.” We will date stamp and mail the postcard back to you.

Discussion

What events have caused this proposed AD? The Civil Aviation Authority (CAA), which is the airworthiness authority for the United Kingdom, recently notified the FAA that an unsafe condition may exist on certain British Aerospace HP137 Mk1, Jetstream series 200, and Jetstream Models 3101 and 3201 airplanes. The CAA reports incidents where cracking has occurred at the base of the thread in the steering jack piston rod, part number 618212, in the nose landing gear unit. The condition could occur on the referenced airplanes that are equipped with nose landing gear unit 1873, B00A702852A, B00A703064A, or B00A703056A. ]

Inadequate clearance or inadequate lubrication of the steering jack pivot points can result in unusually high operational loads. These loads could result in such cracks in the steering jack piston rod.

What are the consequences if the condition is not corrected? A cracked steering jack piston rod could result in failure of the nose wheel steering system with consequent loss of airplane control.

Is there service information that applies to this subject? British Aerospace has issued Mandatory Service Bulletin 32-JA 981043, dated March 5, 1999. This service bulletin:

• Specifies inspecting the steering jack assembly to assure proper clearance between the bush heads on the steering plates and the shim on the steering jack trunnions and to assure that there is adequate lubrication at both trunnions and the eye end fitting;
• Specifies adjusting the clearance and providing adequate lubrication, as necessary; and
• References APPH Ltd. Service Newsletter, Issue 2, Jetstream 31 Steering Jack Part Number 618200. The procedures to accomplish the above-referenced actions are included in this service newsletter.

What action did the CAA take? The CAA classified this service bulletin as mandatory and issued British AD Number 012-03-99, in order to assure the continued airworthiness of these airplanes in the United Kingdom.

Was this in accordance with the bilateral airworthiness agreement? 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 FAA informed of the situation described above.

The FAA's Determination and an Explanation of the Provisions of the Proposed AD

What has FAA decided? The FAA has examined the findings of the CAA; reviewed all available information, including the service information referenced above; and determined that:

• The unsafe condition referenced in this document exists or could develop on other British Aerospace HP137 Mk1, Jetstream series 200, and Jetstream Models 3101 and 3201 airplanes of the same type design;
• The actions specified in the referenced service information should be accomplished on the affected airplanes; and
• AD action should be taken in order to correct this unsafe condition.

What would the proposed AD require? This proposed AD would require you to inspect the steering jack assembly to assure proper clearance between the bush heads on the steering plates and the shim on the steering jack trunnions and to assure that there is adequate lubrication at both trunnions and the eye end fitting. The proposed AD would also require you to adjust the clearance and provide adequate lubrication, as necessary.

Accomplishment of the proposed action would be in accordance with APPH Ltd. Service Newsletter, Issue 2, Jetstream 31 Steering Jack Part Number 618200, as referenced in British Aerospace Mandatory Service Bulletin 32-JA 981043, dated March 5, 1999.

Cost Impact

How many airplanes would the proposed AD impact? We estimate that the proposed AD would affect 300 airplanes in the U.S. registry.

What would be the cost impact of the proposed AD on owners/operators of the affected airplanes? We estimate the following costs to accomplish the proposed inspection:

We estimate the following costs to accomplish any necessary adjustments that would be required based on the results of the proposed inspections. We have no way of determining the number of airplanes that may need such adjustments:

Regulatory Impact

Would this proposed AD impact various entities? 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 proposed rule would not have federalism implications under Executive Order 13132.

Would this proposed AD involve a significant rule or regulatory action? For the reasons discussed above, I certify that this proposed action (1) is not a “significant regulatory action” under Executive Order 12866; (2) is not a “significant rule” under 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 has been placed 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, under 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.