AD 98-04-16

This amendment adopts a new airworthiness directive (AD) that applies to certain Pilatus Aircraft Ltd. (Pilatus) Models PC-12 and PC-12/45 airplanes. This AD requires inspecting the aileron tie-rod jam nuts for looseness, tightening any loose jam nuts, and installing a locking sleeve on both ends of the aileron tie-rod in the chain-drive of the aileron system. The AD results from an incident where the aileron tie-rod jam nuts on the chain-drive of the aileron system became loose. This caused a differential of aileron control between the pilot's control wheel and the co-pilot's control wheel. The actions specified by this AD are intended to prevent such aileron control differential caused by the aileron tie-rod jam nuts becoming loose, which could result in loss of aileron control and consequent loss of control of the airplane.

Final rule

98-04-16 PILATUS AIRCRAFT LTD.: Amendment 39-10328; Docket No. 97-CE-45-AD.

Applicability: Models PC-12 and PC-12/45 airplanes, serial numbers 101 through 169, certificated in any category.

NOTE 1: The modification required by this AD is incorporated at manufacture on Models PC-12 and PC-12/45 airplanes, beginning with serial number 170. Airplanes with this modification are not affected by this AD.

NOTE 2: 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 a differential of aileron control between the pilot's control wheel and the co-pilot's control wheel caused by the aileron tie-rod jam nuts becoming loose, which could result in loss of aileron control and consequent loss of control of the airplane, accomplish the following:

(a) Within the next 100 hours time-in-service (TIS) after the effective date of this AD, inspect the aileron tie-rod jam nuts for looseness in accordance with the Accomplishment Instructions section of Pilatus Service Bulletin No. 27-001, dated March 25, 1997. Prior to further flight, tighten any loose jam nuts in accordance with the above-referenced service bulletin.

(b) Within the next 100 hours TIS after the effective date of this AD, install a locking sleeve on both ends of the aileron tie-rod in the chain-drive of the aileron system in accordance with the Accomplishment Instructions section of Pilatus Service Bulletin No. 27-001, dated March 25, 1997.

(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 time that provides an equivalent level of safety may be approved by the manager, Small Airplane Directorate, 1201 Walnut, suite 900, Kansas City, Missouri 64106. 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.

NOTE 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Small Airplane Directorate.

(e) The inspection, tightening, and installation required by this AD shall be done in accordance with Pilatus Service Bulletin No. 27-001, dated March 25, 1997. 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., CH-6370 Stans, Switzerland. Copies may be inspected at the FAA, Central Region, Office of the Regional Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri, or at the Office of the Federal Register, 800 North Capitol Street, NW, suite 700, Washington, DC.

NOTE 4: The subject of this AD is addressed in Swiss AD HB 97-174, dated April 30, 1997.

(f) This amendment (39-10328) becomes effective on April 2, 1998.

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 Models PC-12 and PC-12/45 airplanes was published in the Federal Register as a notice of proposed rulemaking (NPRM) on October 6, 1997 (62 FR 52055). The NPRM proposed to require inspecting the aileron tie-rod jam nuts for looseness, tightening any loose jam nuts, and installing a locking sleeve on both ends of the aileron tie-rod in the chain-drive of the aileron system. Accomplishment of the proposed actions as specified in the NPRM would be in accordance with Pilatus Service Bulletin No. 27-001, dated March 25, 1997.

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 40 airplanes in the U.S. registry will be affected by this AD, that it will take approximately 5 workhours per airplane to accomplish the required action, and that the average labor rate is approximately $60 an hour. Parts will be provided by the manufacturer at no cost to the owner/operator of the affected airplanes. Based on these figures, the total cost impact of this AD on U.S. operators is estimated to be $12,000, or $300 per airplane.

Regulatory Impact
The regulations adopted herein will 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 final rule does 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) 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 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 USC 106(g), 40113, 44701.

39.13 [Amended]
2. Section 39.13 is amended by adding a new airworthiness directive (AD) to read as follows: