Airworthiness directives: Pilatus Aricraft Ltd.,

[Federal Register: September 28, 1999 (Volume 64, Number 187)]

[Proposed Rules]

[Page 52260-52263]

From the Federal Register Online via GPO Access [wais.access.gpo.gov]

[DOCID:fr28se99-20]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 99-CE-61-AD]

RIN 2120-AA64

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) 98-08-07, which currently requires replacing the rudder and elevator pivot arms with parts of improved design on

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certain Pilatus Aircraft Ltd. (Pilatus) Model PC-7 airplanes. The proposed AD would require replacing the rudder and elevator pivot arms with parts that have been improved since issuance of AD 98-08-07. The proposed AD is the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for Switzerland. The actions specified by the proposed AD are intended to prevent failure of the elevator and rudder caused by fatigue cracking of the pivot arms, which could result in reduced airplane controllability and possible loss of control of the airplane.

DATES: Comments must be received on or before October 27, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 99-CE-61-AD, Room 1558, 601 E. 12th Street, 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 Pilatus Aircraft Ltd., Customer Liaison Manager, CH-6371 Stans, Switzerland; telephone: +41 41 619 65 09; facsimile: +41 41 610 33 51. This information also may be examined at the Rules Docket at the address above.

FOR FURTHER INFORMATION CONTACT: Roman T. Gabrys, Aerospace Engineer, FAA, Small Airplane Directorate, FAA, 1201 Walnut, suite 900, Kansas City, Missouri 64106; telephone: (816) 426-6932; facsimile: (816) 426- 2169.

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 should 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 notice may be changed in light of the comments received.

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 that summarizes each FAA-public contact concerned with the substance of this proposal will be filedin the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this notice must submit a self-addressed, stamped postcard on which the following statement is made: ``Comments to Docket No. 99-CE-61-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, Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 99-CE-61-AD, Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106.

Discussion

AD 98-08-07, Amendment 39-10456 (63 FR 17323, April 9, 1998), currently requires replacing the rudder and elevator pivot arms with the following parts of improved design, on certain Pilatus Model PC-7 airplanes:

Designation

New part No.

Pivot Arm--Left-hand Elevator......................... 113.50.07.108 Pivot Arm--Right-hand Elevator........................ 113.50.07.109 Pivot Arm--Upper Rudder............................... 113.40.07.084 Pivot Arm--Lower Rudder............................... 113.40.07.083

Accomplishment of AD 98-08-07 was required in accordance with Pilatus Service Bulletin No. PC7-55-001, Revision No. 1, dated June 20, 1995.

AD 98-08-07 was the result of reports of cracks in the elevator and rudder trim tab pivot arms on the above-referenced airplanes.

The actions specified in AD 98-08-07 were intended to prevent failure of the elevator and rudder caused by fatigue cracking of the pivot arms, which could result in reduced airplane controllability and possible loss of control of the airplane.

Actions Since Issuance of Previous Rule

The Federal Office for Civil Aviation (FOCA), which is the airworthiness authority for Switzerland, recently notified the FAA that an unsafe condition may exist on certain Pilatus PC-7 airplanes. The FOCA of Switzerland advises that cracks have been found in the improved design rudder and elevator pivot arms that are specified in Pilatus Service Bulletin No. PC7-55-001, Revision No. 1, dated June 20, 1995, and mandated to be installed by AD 98-08-07.

Analyis reveals that the cause of the cracks is due to a manufacturing defect where the manufacturing process deviated from the design specifications.

Relevant Service Information

Pilatus has issued Service Bulletin No. 55-003, dated July 7, 1999, which specifies procedures for replacing the rudder and elevator pivot arms with parts of improved design, as follows:

Previous part No. Designation

installed per AD New part No. 98-08-07

Pivot Arm, Inner Elevator.... 113.50.07.108 113.50.07.108 (green paint). Pivot Arm, Outer Elevator.... 113.50.07.109 113.50.07.109 (green paint). Pivot Arm, Upper Rudder...... 113.40.07.084 113.40.07.084 (green paint). Pivot Arm, Lower Rudder...... 113.40.07.083 113.40.07.083 (green paint).

The FOCA classified this service bulletin as mandatory and issued Swiss Airworthiness Directive HB 99-412, Effective Date: August 31, 1999, in order to assure the continued airworthiness of these airplanes in Switzerland.

The FAA's Determination

This airplane model is manufactured in Switzerland and is type certificated for operation in the United States under

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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 FOCA of Switzerland has kept the FAA informed of the situation described above.

The FAA has examined the findings of the FOCA; reviewed all available information, including the referenced service 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 the Provisions of the Proposed AD

Since an unsafe condition has been identified that is likely to exist or develop in other Pilatus PC-7 airplanes of the same type design registered for operation in the United States, the FAA is proposing AD action to supersede AD 98-08-07. The proposed AD would require replacing the rudder and elevator pivot arms with parts that have been improved since issuance of AD 98-08-07.

Cost Impact

The FAA estimates that 8 airplanes in the U.S. registry would be affected by the proposed AD, that it would take approximately 6 workhours per airplane to accomplish the proposed action, and that the average labor rate is approximately $60 an hour. Parts cost approximately $300 per airplane. Based on these figures, the total cost impact of the proposed AD on U.S. operators is estimated to be $5,280, or $660 per airplane.

Regulatory Impact

The regulations proposed herein 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. Therefore, in accordance with Executive Order 12612, it is determined that this proposal would not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.

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, 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.

   Sec. 39.13 [Amended]

2. Section 39.13 is amended by removing Airworthiness Directive (AD) 98-08-07, Amendment 39-10456, and by adding a new AD to read as follows:

   Pilatus Aircraft Ltd.: Docket No. 99-CE-61-AD; Supersedes AD 98-08- 07, Amendment 39-10456.

   Applicability: Model PC-7 airplanes, manufacturer serial number (MSN) 001 through MSN 614, certificated in any category.

   Note 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (d) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

   Compliance: Required as indicated in the body of this AD, unless already accomplished.

   To prevent fatigue failure of the elevator and rudder trim tab pivot arms because of cracks, which could result in the loss of airplane control, accomplish the following:

   (a) Within the next 100 hours time-in-service (TIS) after the effective date of this AD, replace the rudder and elevator pivot arms with parts of improved design (or FAA-approved equivalent part numbers), as specified in and in accordance with Pilatus Service Bulletin No. 55-003, dated July 7, 1999. The part numbers of the improved design pivot arms are reflected in the following chart:

   Previous part No. Designation

   installed per AD

   New part No. 98-08-07

   Pivot Arm, Inner Elevator.... 113.50.07.108 113.50.07.108 (green paint). Pivot Arm, Outer Elevator.... 113.50.07.109 113.50.07.109 (green paint). Pivot Arm, Upper Rudder...... 113.40.07.084 113.40.07.084 (green paint). Pivot Arm, Lower Rudder...... 113.40.07.083 113.40.07.083 (green paint).

   (b) As of the effective date of this AD, no person may install, on any of the affected airplanes, an elevator or rudder pivot arm that is not of the improved design specified in paragraph (a) of this AD.

   (c) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished.

   (d) An alternative method of compliance or adjustment of the compliance times that provides an equivalent level of safety may be approved by the Manager, Small Airplane Directorate, 1201 Walnut, suite 900, Kansas City, Missouri 64106.

   (1) The request shall be forwarded through an appropriate FAA Maintenance Inspector, who may add comments and then send it to the Manager, Small Airplane Directorate.

   (2) Alternative methods of compliance approved in accordance with AD 98-08-07 are not considered approved as alternative methods of compliance for this AD.

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   Note 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Small Airplane Directorate.

   (e) Questions or technical information related to Pilatus Service Bulletin No. 55-003, dated July 7, 1999, should be directed to Pilatus Aircraft Ltd., Customer Liaison Manager, CH-6371 Stans, Switzerland; telephone: +41 41 619 65 09; facsimile: +41 41 610 33 51. This service information may be examined at the FAA, Central Region, Office of the Regional Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106.

   Note 3: The subject of this AD is addressed in Swiss Airworthiness Directive HB 99-412, Effective Date: August 31, 1999.

   (f) This amendment supersedes AD 98-08-07, Amendment 39-10456.

   Issued in Kansas City, Missouri, on September 20, 1999. Michael Gallagher, Manager, Small Airplane Directorate, Aircraft Certification Service.

   [FR Doc. 99-25222Filed9-27-99; 8:45 am]

   BILLING CODE 4910-13-U