AD 2003-09-01

This amendment adopts a new airworthiness directive (AD) that applies to all Pilatus Aircraft Ltd. (Pilatus) Model PC-6 airplanes. This AD requires you to inspect and correct, as necessary, the aileron control bellcrank assemblies at the wing and fuselage locations. 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 detect and correct increased friction in the aileron control bellcrank assemblies, which could result in failure of the aileron flight-control system. Such failure could lead to problems in controlling flight.

Final rule.

2003-09-01 Pilatus Aircraft Ltd.: Amendment 39-13130; Docket No. 2003-CE-01-AD.

(a) What airplanes are affected by this AD? This AD affects Model PC-6 airplanes, all manufacturer serial numbers (MSN) up to and including 939, that are certificated in any category.

(b) Who must comply with this AD? Anyone who wishes to operate any of the airplanes identified in paragraph (a) of this AD must comply with this AD.

(c) What problem does this AD address? The actions specified by this AD are intended to detect and correct increased friction in the aileron control bellcrank assemblies, which could result in failure of the aileron flight-control system. Such failure could lead to problems in controlling flight.

(d) What actions must I accomplish to address this problem? To address this problem, you must accomplish the following:

Actions
Compliance
Procedures
(1) Inspect, before removal, the wing bellcrank assemblies, part numbers (P/N) 6132.0071.51 and 6132.0071.52, for installed circlips, P/N N237.

(i) If circlips are installed, perform the actions required in paragraphs (d)(5) and (d)(6).

(ii) If circlips are not installed, perform all actions required by paragraphs (d)(3), (d)(4), (d)(5), (d)(6), and (d)(7).
Within the next 100 hours time-in-service (TIS) after June 17, 2003 (the effective date of this AD), unless already accomplished.
In accordance with Pilatus Aircraft Ltd. PC-6 Service Bulletin No. 27-001, dated June 5, 2002, and the applicable maintenance manual.
(2) Inspect, before removal, the fuselage bellcrank assembly, P/N 6232.0118.00, for the circlip installed on the housing to prevent axial movement of the bellcrank on its bearing and the flange of the housing to the rear. If the fuselage bellcrank assembly has either no circlip and/or is not installed as required, perform the actions in paragraphs (d)(8) and (d)(9).
Prior to further flight after the inspection required in paragraph (d)(1) of this AD.
In accordance with Pilatus Aircraft Ltd. PC-6 Service Bulletin No. 27-001, dated June 5, 2002, and the applicable maintenance manual.
(3) Remove the wing bellcrank assemblies, P/Ns 6132.0071.51 and 6132.0071.52, and inspect for worn or damaged bearings. Replace worn or damaged bearings.
Prior to further flight after the inspections required in paragraphs (d)(1) and (d)(2) of this AD, as applicable.
In accordance with Pilatus Aircraft Ltd. PC-6 Service Bulletin No. 27-001, dated June 5, 2002, and the applicable maintenance manual.
(4) Stake and lock the bearing in the housing of the wing bellcranks, P/Ns 6132.0071.51 and 6132.0071.52.
Prior to further flight after the inspections required in paragraphs (d)(1) and (d)(2) of this AD, as applicable.
In accordance with Pilatus Aircraft Ltd. PC-6 Service Bulletin No. 27-001, dated June 5, 2002, and the applicable maintenance manual.
(5) Inspect the wing bellcranks control-cable attachment bolts for correct type and for signs of rub damage on the heads. Replace bolts which are damaged and/or have a total length (including head) of more than 21.5 mm (0.85 in.).
Prior to further flight after the inspections required in paragraphs (d)(1) and (d)(2) of this AD.
In accordance with Pilatus Aircraft Ltd. PC-6 Service Bulletin No. 27-001, dated June 5, 2002, and the applicable maintenance manual.
(6) Inspect the wing bellcranks support plate for signs of rub damage caused by the bolts. If damage is found:.

(i) Obtain a repair scheme from the manufacturer through FAA at the address specified in paragraph (f) of this AD.

(ii) Incorporate this repair scheme.
Prior to further flight after the inspections required in paragraphs (d)(1) and (d)(2) of this AD.
In accordance with Pilatus Aircraft Ltd. PC-6 Service Bulletin No. 27-001, dated June 5, 2002, and the applicable maintenance manual.
(7) Reinstall wing bellcrank assemblies
Prior to further flight after the inspections required in paragraphs (d)(1) and (d)(2) of this AD.
Inaccordance with Pilatus Aircraft Ltd. PC-6 Service Bulletin No. 27-001, dated June 5, 2002, and the applicable maintenance manual.
(8) Remove the fuselage bellcrank assembly, P/N 6232.0118.00, and inspect the housing for wear, damage, and signs of axial movement of the bearing in the housing. Replace worn or damaged bearings. If any signs of axial movement of a bearing are found:

(i) Obtain a repair scheme from the manufacturer through FAA at the address specified in paragraph (f) of this AD.

(ii) Incorporate this repair scheme.
Prior to further flight after the inspections required in paragraphs (d)(1) and (d)(2) of this AD.
In accordance with Pilatus Aircraft Ltd. PC-6 Service Bulletin No. 27-001, dated June 5, 2002, and the applicable maintenance manual.
(9) Reinstall the fuselage bellcrank assembly. Ensure that the fuselage bellcrank assembly is installed so that the surface of the bellcrank with the flange of the housing is installed to the rear. The effect of this isto lock the bellcrank on the bearing tube and thus prevent movement.
Prior to further flight after the inspections required in paragraphs (d)(1), (d)(2) and d)(8) of this AD.
In accordance with Pilatus Aircraft Ltd. PC-6 Service Bulletin No. 27-001, dated June 5, 2002, and the applicable maintenance manual.
(10) Do not install any bellcrank assemblies, P/Ns 6132.0071.51, 6132,0071.52, and 6232.0118.00 (or FAA-approved equivalent part numbers), unless the aileron assembly has been inspected, modified, and installed.
As of June 17, 2003 (the effective date of this AD).
In accordance with Pilatus Aircraft Ltd. PC-6 Service Bulletin No. 27-001, dated June 5, 2002, and the applicable maintenance manual.

Note 1: Axial movement of serviceable bearings in the housings of the wing bellcranks is permitted provided no wear or damage to the bearing is found.

Note 2: Any signs of axial movement of a bearing in the housing of the fuselage bellcrank assembly requires that you obtain a repair scheme from the manufacturer through FAA at the address specified in paragraph (f) of this AD and incorporate the repair scheme.

(e) Can I comply with this AD in any other way? You may use an alternative method of compliance or adjust the compliance time if:

(1) Your alternative method of compliance provides an equivalent level of safety; and

(2) The Standards Office Manager, Small Airplane Directorate, approves your alternative. Submit your request through an FAA Principal Maintenance Inspector, who may add comments and then send it to the Standards Office Manager.

Note 3: This AD applies to each airplane identified in paragraph (a) of this AD, 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 (e) 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 you have not eliminated the unsafe condition, specific actions you propose to address it.

(f) Where can I get information about any already-approved alternative methods of compliance? Contact Doug Rudolph, Aerospace Engineer, FAA, Small Airplane Directorate, 901 Locust, Room 301, Kansas City, Missouri 64106; telephone: (816) 329-4059; facsimile: (816) 329-4090.

(g) What if I need to fly the airplane to another location to comply with this AD? The FAA can issue a special flight permit under 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate your airplane to a location where you can accomplish the requirements of this AD.

(h) Are any service bulletins incorporated into this AD by reference? Actions required by this AD must be donein accordance with Pilatus Aircraft Ltd. PC-6 Service Bulletin No. 27-001, dated June 5, 2002. The Director of the Federal Register approved this incorporation by reference under 5 U.S.C. 552(a) and 1 CFR part 51. You may get copies from Pilatus Aircraft Ltd., Customer Liaison Manager, CH-6371 Stans, Switzerland; telephone: +41 41 619 63 19; facsimile: +41 41 619 6224; or from Pilatus Business Aircraft Ltd., Product Support Department, 11755 Airport Way, Broomfield, Colorado 80021; telephone: (303) 465-9099; facsimile: (303) 465-6040. You may view copies 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 4: The subject of this AD is addressed in Swiss AD Number HB 2002-642, dated November 15, 2002.

(i) When does this amendment become effective? This amendment becomes effective on June 17, 2003.

Discussion

What events have caused this AD? The Federal Office for Civil Aviation (FOCA), which is the airworthiness authority for Switzerland, recently notified FAA that an unsafe condition may exist on all Pilatus Model PC-6 airplanes. The FOCA reports one occurrence where the pilot reported increased friction on the ailerons. Inspection revealed unwanted axial movement of the aileron bellcrank assemblies, part numbers 6132.0071.51, 6132.0071.52, and 6232.0118.00. The axial movement is caused by deterioration of the adhesive bond around the bellcrank bearings which could cause the heads of the control cable attachment bolts to catch on the adjacent structure.

Has FAA taken any action to this point? We issued 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 Model PC-6 airplanes. This proposal was published in the Federal Register as a notice of proposed rulemaking (NPRM) on February 12, 2003 (68 FR 7081). The NPRM proposed to you to inspect and correct, as necessary, the aileron control bellcrank assemblies at the wing and fuselage locations.

What is the potential impact if FAA took no action? Increased friction in the aileron control bellcrank assemblies could result in failure of the aileron flight-control system. Such failure could lead to problems in controlling flight.

Was the public invited to comment? The FAA encouraged interested persons to participate in the making of this amendment. We did not receive any comments on the proposed rule or on our determination of the cost to the public.

FAA's Determination

What is FAA's final determination on this issue? We carefully reviewed all available information related to the subject presented above and determined that air safety and the public interest require the adoption of the rule as proposed except for the changes discussed above and minor editorial questions. We havedetermined that these changes and minor corrections:

--Provide the intent that was proposed in the NPRM for correcting the unsafe condition; and

--Do not add any additional burden upon the public than was already proposed in the NPRM.

Cost Impact

How many airplanes does this AD impact? We estimate that this AD affects 32 airplanes in the U.S. registry.

What is the cost impact of this AD on owners/operators of the affected airplanes? We estimate the following costs to accomplish the inspections and modifications:

Labor cost
Parts cost
Total cost per airplane
Total cost on U.S. operators
7 workhours x $60 per hour = $420
$300
$720
$720 x 32 = $23,040.

We have no way of estimating costs to accomplish any necessary repairs that would be required based on the results of the inspections. We have no way of determining the number of airplanes that may need such repair.

Regulatory Impact

Does this AD impact various entities? 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.

Does this 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) 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, under 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. FAA amends 39.13 by adding a new AD to read as follows: