Airworthiness Directives; British Aerospace H.P. 137 Mk1, Jetstream Series 200, and Jetstream Model 3101 Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes to supersede Airworthiness Directive (AD) 98-13-03, which currently requires repetitive inspections of the main landing gear (MLG) hinge fittings, support angles, and attachment bolts on British Aerospace H.P. 137 Mk1, Jetstream series 200, and Jetstream Model 3101 airplanes. This AD also requires eventual installation of improved design MLG hinge fittings as terminating action for the repetitive inspections of the hinge fittings and attachment bolts. This AD specifies repetitive inspections of the support angles for those airplanes with the approved design MLG hinge fittings installed. However, the applicability of AD 98-13-03 exempts those airplanes with the improved design MLG hinge fittings installed from the actions of the AD. The proposed AD would retain the requirements of AD 98-13-03 and would remove from the applicability the exemption of those airplanes with the improved design MLG hinge fittings installed. The actions specified by the proposed AD are intended to detect, correct, and prevent future fatigue cracking of the MLG, which could result in structural failure of the MLG and consequent loss of airplane control during takeoff, landing, or taxi operations.

DATES:

The Federal Aviation Administration (FAA) must receive any comments on this rule on or before August 30, 2001.

ADDRESSES:

Submit comments in triplicate to FAA, Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 2000-CE-58-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. Doug Rudolph, Aerospace Engineer, FAA, Small Airplane Directorate, 901 Locust, Room 301, Kansas City, Missouri 64106; telephone: (816) 329-4059; 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 clear, 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. 2000-CE-58-AD.” We will date stamp and mail the postcard back to you.

Discussion

Has FAA Taken Any Action on the Main Landing Gear (MLG) Hinge Fittings, Support Angles, and Attachment Bolts on British Aerospace H.P. 137 Mk1, Jetstream Series 200, and Jetstream Model 3101 Airplanes to This Point?

On June 8, 1998, FAA issued AD 98-13-03, Amendment 39-10591 (63 FR 33532, June 19, 1998). This AD currently requires the following on the above-referenced airplanes:

—Repetitive inspections of the MLG hinge fitting, support angles, and attachment bolts, and repairing or replacing any part that is cracked; and

—Eventual installation of improved design MLG hinge fittings, part number (P/N) 1379133B1 and 1379133B2 (Modification 5218), as terminating action for the repetitive inspections of the hinge fittings and attachment bolts. This AD specifies repetitive inspections of the support angles for those airplanes with the approved design MLG hinge fittings installed. However, the applicability of AD 98-13-03 exempts those airplanes with the improved design MLG hinge fittings installed from the actions of the AD.

Accomplishment of these actions is required in accordance with the following service information:

—British Aerospace Jetstream Mandatory Service Bulletin (MSB) No. 7/5, which includes procedures for inspecting the left and right main landing gear hinge attachment nuts to the auxiliary and aft spars for signs of relative movement between the nuts and hinge fitting on H.P. 137 MK1 and Jetstream series 200 airplanes. This MSB incorporates the following effective pages:

—British Aerospace MSB No. 7/8, which includes procedures for inspecting the MLG hinge fitting for cracks, and repairing cracked hinge fittings on H.P. 137 MK1 and Jetstream series 200 airplanes. This MSB incorporates the following effective pages:

—Jetstream Alert Service Bulletin (ASB) 32-A-JA 850127, which includes procedures for inspecting the MLG hinge fitting and support angle for cracks on Jetstream Model 3101 airplanes. This ASB incorporates the following effective pages:

—Jetstream Service Bulletin (SB) 57-JM 5218 which includes procedures for installing improved design MLG hinge fittings, P/N 1379133B1 and 1379133B2 (Modification 5218), on H.P. 137 Mk1, Jetstream series 200, and certain Jetstream Model 3101 airplanes. This SB incorporates the following effective pages:

The actions of AD 98-13-03 are consistent with the FAA's aging commuter aircraft policy, which briefly states that, when a modification exists that could eliminate or reduce the number of required critical inspections, the modification should be incorporated. This policy is based on the FAA's determination that reliance on critical repetitive inspections on airplanes utilized in commuter service carries an unnecessary safety risk when a design change exists that could eliminate or, in certain instances, reduce the number of those critical inspections.

The alternative to installing improved design MLG hinge fittings would be to repetitively inspect this area for the life of the airplane.

What Has Happened Since AD 98-13-03 To Initiate This Action?

The applicability of AD 98-13-03 exempts those airplanes with the improved design MLG hinge fittings installed from the actions of the AD. The exemption of those airplanes with the improved design MLG hinge fittings installed should be removed and all affected airplanes should have the support angles repetitively inspected.

The FAA's Determination and Explanation of the Provisions of the Proposed AD. What Has FAA Decided?

After examining the circumstances and reviewing all available information related to the information described above, we have determined that:

—The unsafe condition referenced in this document exists or could develop on other British Aerospace H.P. 137 Mk1, Jetstream series 200, and Jetstream Model 3101 airplanes of the same type design;

—The repetitive inspections of the MLG support angles should be accomplished on all affected airplanes, even those with the improved design MLG hinge fittings installed; and

—AD action should be taken in order to detect, correct, and prevent future fatigue cracking of the MLG, which could result in structural failure of the MLG and consequent loss of airplane control during takeoff, landing, or taxi operations.

What Would the Proposed AD Require?

This proposed AD would supersede AD 98-13-03 with a new AD that would:

—Retain the requirements of repetitively inspecting the main landing gear (MLG) hinge fittings, support angles, and attachment bolts and repairing any cracked part;

—Require eventual installation of improved design MLG hinge fittings as terminating action for the repetitive inspections of the hinge fittings and attachment bolts; and

—Require repetitive inspections of the MLG support angles on all affected airplanes, even those with the improved design MLG hinge fittings installed.

Accomplishment of the proposed actions would be required in accordance with the previously-referenced service information.

Cost Impact

How Many Airplanes Would the Proposed AD Impact?

We estimate that the proposed AD affects up to 236 airplanes in the U.S. registry.

What Would Be the Cost Impact of the Proposed AD on Owners/Operators of the Affected Airplanes?

The FAA estimates that the proposed AD would affect 71 airplanes in the U.S. registry. We estimate the following costs to accomplish the proposed actions:

The cost figures presented above are the same as those presented in AD 98-13-03. The only additional impact the proposed AD would have is the repetitive support angle inspections on those airplanes with improved design hinge installations at the effective date of AD 98-13-03.

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 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 14 CFR part 39 of the Federal Aviation Regulations 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.