Airworthiness Directives; Aerostar Aircraft Corporation Models PA-60-600 (Aerostar 600), PA-60-601 (Aerostar 601), PA-60-601P (Aerostar 601P), PA-60-602P (Aerostar 602P), and PA-60-700P (Aerostar 700P) 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 all Aerostar Aircraft Corporation (Aerostar) Models PA-60-600, PA-60-601, PA-60-601P, PA-60-602P and PA-60-700P airplanes. The proposed AD would require you to replace both of the existing main landing gear lower side brace assemblies with parts of improved design. The proposed AD is the result of several reports of cracking of the main landing gear lower side brace at the upper bolt lug discovered on preflight inspection. The actions specified by the proposed AD are intended to correct damage or cracks in the main landing gear lower side brace at the upper bolt lug where the upper and lower side braces connect. This could result in cracking and failure of the main landing gear lower side brace. Such failure could lead to loss of control of the airplane.

DATES:

The Federal Aviation Administration (FAA) must receive any comments on this rule by December 29, 2000.

ADDRESSES:

Send comments in triplicate to the Federal Aviation Administration (FAA), Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 2000-CE-31-AD, 901 Locust, Room 506, Kansas City, Missouri 64106. You may look at comments at this location between 8 a.m. and 4 p.m., Monday through Friday, except holidays.

You may get the service information referenced in the proposed AD from Aerostar Aircraft Corporation, 10555 Airport Drive, Hayden Lake, ID 83835; telephone: (208) 762-0338; facsimile: (208) 762-8349. You may read this information at the Rules Docket at the address above.

FOR FURTHER INFORMATION CONTACT:

Richard Simonson, Aerospace Engineer, FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW, Renton, Washington 98055; telephone: (425) 227-2597; facsimile: (425) 227-1181.

SUPPLEMENTARY INFORMATION:

Comments Invited

How do I comment on this proposed AD?

We invite your comments on the proposed rule. You may send whatever written data, views, or arguments you choose. You need to include the rule's docket number and send your comments in triplicate to the address mentioned under the caption ADDRESSES. We will consider all comments received by the closing date mentioned above, before acting on the proposed rule. We may change the proposals contained in this notice because of the comments received.

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 call for a need to change the proposed rule. You may examine all comments we receive. We will file a report in the Rules Docket that summarizes each FAA contact with the public that concerns the substantive parts of this proposal.

The FAA is reexamining 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 the ease of understanding this document, 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.faa.gov/language/.

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-31-AD.” We will date stamp and mail the postcard back to you.

Discussion

What events have caused this AD?

The FAA has received several reports of cracking of the main landing gear lower side brace at the upper bolt lug discovered on preflight inspection.

What are the consequences if the condition is not corrected?

Damage or cracking of the main landing gear lower side brace, if not detected and corrected, could result in failure of this part. Such failure could lead to loss of the main landing gear with consequent loss of control of the airplane.

Relevant Service Information

Is there service information that applies to this subject?

Aerostar has issued Service Bulletin SB600-134A, dated March 31, 2000.

What are the provisions of this service bulletin?

The service bulletin includes procedures for replacing both existing main landing gear lower side brace assemblies with parts of improved design, Aerostar part number 400084-001, lower side brace assemblies.

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

What has FAA decided?

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

—the unsafe condition referenced in this document exists or could develop on other Aerostar Models PA-60 series airplanes of the same type design;

—the actions specified in the previously-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 incorporate the actions in Part II of the previously referenced service bulletin.

Cost Impact

How many airplanes would the proposed AD impact?

We estimate that the proposed AD affects 650 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 do the proposed modification:

Regulatory Impact

Would this proposed AD impact relations between Federal and State governments?

The proposed regulations would not have substantial direct effects 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. We have 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 put into effect, 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. You may get a copy 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.