AD 2000-01-10

This amendment supersedes Airworthiness Directive (AD) 98-08-07, which currently requires replacing the rudder and elevator pivot arms with parts of improved design on certain Pilatus Aircraft Ltd. (Pilatus) Model PC-7 airplanes. This AD requires replacing the rudder and elevator pivot arms with parts that have been improved since issuance of AD 98-08-07. This AD is the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for Switzerland. The actions specified by this 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.

Final rule

2000-01-10 PILATUS AIRCRAFT LTD.: Amendment 39-11508; Docket No. 99-CE-61-AD; Supersedes AD 98-08-07, Amendment 39-10456. Applicability: Model PC-7 airplanes, all manufacturer serial numbers (MSN) up to and including 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:

Designation
Previous Part
Number Installed
per AD 98-08-07

New Part Number
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, 901 Locust, Room 301, 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 AD98-08-07 are not considered approved as alternative methods of compliance for this AD.

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, 901 Locust, Room 506, Kansas City, Missouri 64106.

(f) The replacements required by this AD shall be done in accordance with Pilatus Service Bulletin No. 55-003, dated July 7, 1999. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Pilatus Aircraft Ltd., Customer Liaison Manager, CH-6371 Stans, Switzerland. Copies may be inspected at the FAA, Central Region, Office of the Regional Counsel, 901 Locust, Room 506, Kansas City, Missouri, or at the Office of the Federal Register, 800 North Capitol Street, NW, suite 700, Washington, DC.

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

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

(h) This amendment becomes effective on March 3, 2000.

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

Events Leading to the Issuance of This AD
A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an AD that would apply to certain Pilatus PC-7 airplanes was published in the Federal Register as a notice of proposed rulemaking (NPRM) on September 28, 1999 (64 FR 52260). The NPRM proposed to supersede AD 98-08-07, Amendment 39-10456 (63 FR 17323, April 9, 1998). AD 98-08-07 currently requires replacing the rudder and elevator pivot arms with parts of improved design.

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 NPRM proposed to require replacing the rudder and elevator pivot arms with parts that have been improved since issuance of AD 98-08-07.

Accomplishment of the proposed action as specified in the NPRM would be required in accordance with Pilatus Service Bulletin No. 55-003, dated July 7, 1999.

The NPRM was the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for Switzerland Interested persons have been afforded an opportunity to participate in the making of this amendment. No comments were received on the proposed rule or the FAA's determination of the cost to the public.

The FAA's Determination
After careful review of all available information related to the subject presented above, the FAA has determined that air safety and the public interest require the adoption of the rule as proposed except for minor editorial corrections. The FAA has determined that these minor corrections will not change the meaning of the AD and will not add any additional burden upon the public than was already proposed.

Cost Impact
The FAA estimates that 8 airplanes in the U.S. registry will be affected by this AD, that it will take approximately 6 workhours per airplane to accomplish the required 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 this AD on U.S. operators is estimated to be $5,280, or $660 per airplane.

Regulatory Impact
The regulations adopted herein will 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 final rule does not have federalism implications under Executive Order 13132.

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) will not havea 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 final evaluation prepared for this action is contained 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, Incorporation by reference, Safety.

Adoption of the Amendment
Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends 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.

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: