Airworthiness Directives; Pilatus Aircraft Ltd. Model PC-7 Airplanes.

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes to supersede Airworthiness Directive (AD) 98-08-22, which currently requires inspecting the elevator and rudder attachment brackets for cracks and corrosion, and replacing any cracked or corrosion-damaged parts on certain Pilatus Aircraft Ltd. (Pilatus) Model PC-7 airplanes. AD 98-08-22 resulted from mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for Switzerland. Since the issuance of AD 98-08-22, Pilatus has redesigned the brackets. Installation of these brackets should eliminate the cause of corrosion, which resulted in cracks or corrosion damage. The proposed AD would require you to replace the elevator and rudder attachment brackets with parts of improved design. The actions specified by the proposed AD are intended to prevent failure of the elevator and rudder attachment brackets because of cracks or corrosion damage. Such failure could result in the elevator or rudder separating from the airplane with consequent loss of airplane control.

DATES:

The Federal Aviation Administration (FAA) must receive any comments on this proposed rule by February 5, 2001.

ADDRESSES:

Send three copies of your comments to FAA, Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 2000-CE-46-AD, 901 Locust, Room 506, Kansas City, Missouri 64106. You may read comments at this location between 8 a.m. and 4 p.m., Monday through Friday, except holidays.

You may get service information that applies to the proposed AD from Pilatus Aircraft Ltd., Customer Liaison Manager, CH-6371 Stans, Switzerland; telephone: +41 41 619 6509; facsimile: +41 41 610 3351. You may read this information at the Rules Docket at the address above.

FOR FURTHER INFORMATION CONTACT:

Roman Gabrys, Aerospace Engineer, FAA, Small Airplane Directorate, 901 Locust, Room 301, Kansas City, Missouri 64106; telephone: (816) 329-4141; facsimile: (816) 329-4090.

SUPPLEMENTARY INFORMATION:

Comments Invited

How do I comment on the 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 specified under the caption ADDRESSES. We will consider all comments received by the closing date specified above, before acting on the proposed rule. We may change the proposals contained in this notice in light 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 require a change to the proposed rule. You may look at 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.

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 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-46-AD.” We will date stamp and mail the postcard back to you.

Discussion

Has FAA taken any action to this point? Reports received from the Federal Office for Civil Aviation (FOCA), which is the airworthiness authority for Switzerland, revealed instances of corrosion and cracking in the elevator and rudder attachment brackets on Pilatus Model PC-7 airplanes that have been operated in areas of high humidity or salt content. This caused FAA to issue AD 98-08-22, Amendment 39-10471 (63 FR 19175, April 17, 1998). That AD requires you to inspect the elevator and rudder attachment brackets for cracks and/or corrosion, and replace any cracked or corrosion-damaged parts, as applicable.

What has happened since AD 98-08-22 to initiate this action? The FOCA recently notified FAA of the need to change AD 98-08-22. The FOCA reports that Pilatus has redesigned the elevators and rudder attachment brackets. Installation of these brackets should inhibit the cause of corrosion, which resulted in cracks or corrosion damage.

Is there service information that applies to this subject? Pilatus has issued Service Bulletin No. 55-005, dated March 23, 2000.

What are the provisions of this service bulletin? The service bulletin includes procedures for removing and replacing the elevator and rudder attachment brackets with ones of improved design.

What action did FOCA take? The FOCA classified this service bulletin as mandatory and issued Swiss AD Number HB 2000-411, dated September 27, 2000, to ensure the continued airworthiness of these airplanes in Switzerland.

Was this in accordance with the bilateral airworthiness agreement? These airplane models are manufactured in Switzerland 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.

Following this bilateral airworthiness agreement, the FOCA 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 FOCA; 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 Pilatus Model PC-7 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 supersede AD 98-08-22 with a new AD that would require you to incorporate the actions in the previously referenced service bulletin.

Why is the compliance of the initial inspection in hours time-in-service (TIS) and calendar time? The affected airplanes are used in general aviation operations. Those operators may accumulate 100 hours TIS on the airplane in less than 3 months. We have determined that the dual compliance time:

—Gives all owners/operators of the affected airplanes adequate time to schedule and do the actions in this proposed AD; and

—Ensures that the unsafe condition referenced in this AD will be corrected within a reasonable time period without inadvertently grounding any of the affected airplanes.

Cost Impact

How many airplanes would the proposed AD impact? We estimate that the proposed AD affects 8 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 various entities? The regulations proposed here 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 adopted, 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.