AD 2002-14-22

This amendment adopts a new airworthiness directive (AD) that applies to all Pilatus Aircraft Ltd. (Pilatus) Models PC-12 and PC-12/45 airplanes. This AD requires you to inspect the left and right main landing gear (MLG) assemblies for bolts with a serial number (S/N) beginning with the letters "AT" and numbers 299 or lower and replace each bolt with a bolt that does not have a S/N with both the letters "AT" and a number of 299 or lower. 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 replace defective MLG assembly bolts that have an improper cadmium plating, which could cause hydrogen embrittlement and bolt failure. Such failure could lead to MLG collapse during landing.

Final rule.

2002-14-22--Pilatus Aircraft Ltd.: Amendment 39-12822; Docket No. 2001-CE-44-AD.

(a) What airplanes are affected by this AD? This AD affects the following airplane models and serial numbers that are certificated in any category:

(1) Group 1: Pilatus may have installed the affected bolts on the following airplanes at manufacture. All portions of this AD apply to these airplanes:

Model
Serial Nos.
PC-12 and PC-12/45
349, 352, 357, 359, 362 through 365, 367, 369, 371, 375, 377, 380, 384, 385, 388, 390, 391, 393, 401, and 409.

(2) Group 2: The affected bolts could be installed through spare replacement on any of the following model airplanes. Paragraphs (d)(3) and (d)(4) of this AD apply to these airplanes:

Model
Serial Nos.
PC-12 and PC-12/45
All serial numbers

(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 replace defective main landing gear (MLG) assembly bolts that have an improper cadmium plating, which could cause hydrogen embrittlement and bolt failure.

(d) What actions must I accomplish to address this problem? To address this problem, accomplish all actions for Group 1 airplanes, and accomplish paragraphs (d)(3) and (d)(4) of this AD for Group 2 airplanes:

Actions
Compliance
Procedures
(1) Inspect the left and right main landing gear (MLG) assembly for the
existence of a bolt , part number (P/N) 532.10.12.077, that has a serial number (S/N) with both the letters "AT" and a number of 299 or lower.

(i) If the above referenced bolts are not installed, no further action is required.

(ii) If the above referenced bolts are installed, replace each bolt with an FAA-approved bolt that does not have a S/N with both the letters "AT" and a number of 299 or lower.
Inspect within the next 30 days after August 29, 2002 (the effective date of this AD). Prior to further flight, replace bolts found during the inspection required in paragraph (d)(1) of this AD.
Pilatus PC-12 Service bulletin No. 32-012, dated October 18, 2001, provides information about these actions.
(2) Send the removed bolts to Pilatus Aircraft Ltd. so the bolts cannot be reused and report the results of the inspection (positive or negative) to FAA. The Office of Management and Budget (OMB) approved the information collection requirements contained in this regulation under the provisions of the Paperwork Reduction Act of 1980 (44 U.S.C. 3501 et seq.) and assigned OMB Control Number 2120-0056.
Within 10 days after removing the bolts or within 10 days after August 29, 2002 (the effective date of this AD), whichever occurs later.
Send the removed bolts to Pilatus Aircraft Ltd. at the address in paragraph (h) of this AD, and send the report to Doug Rudolph, FAA, at the address in paragraph (f)of this AD.
(3) Do not install any bolt, P/N 532.10.12.077, on any MLG assembly
that has a S/N with both the letters "AT" and a number of 299 or lower.
As of August 29, 2002 (the effective date of this AD).
Not Applicable.
(4) If you have already accomplished the actions specified in Pilatus PC-12 Service Bulletin No. 32-012, dated October 18, 2001, send a report to the FAA at the address in paragraph (f) of this AD, stating if one of the affected bolts was replaced and returned to Pilatus.
Within the next 30 days after August 29, 2002 (the effective date of this AD).
Not Applicable.

(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 Manager, Small Airplane Directorate, approves your alternative. Submit your request through an FAA Principal Maintenance Inspector, who may add comments and thensend it to the Manager, Small Airplane Directorate.

Note 1: 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 sections 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 done in accordance with Pilatus PC-12 Service Bulletin No. 32-012, dated October 18, 2001. 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.

(i) When does this amendment become effective? This amendment becomes effective on August 29, 2002.

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 certain Pilatus Models PC-12 and PC-12/45 airplanes. The FOCA reports that, because of a manufacturing defect, certain bolts on the main landing gear (MLG) assembly may be defective. The problem is caused by an improper cadmium process applied to the high strength steel part, which can cause hydrogen embrittlement and subsequent failure of the bolt.

The defective bolts were initially installed on MLG assemblies that have a serial number beginning with the letters "AM". Each bolt in the defective lot incorporates the letters "AT" and a number of 299 or lower.

What Is the Potential Impact if FAA Took No Action?

If not corrected, such failure could lead to MLG collapse during landing.

Has FAA Taken Any Action to This Point?

Weissued a proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an AD that would apply to all Pilatus Models PC-12 and PC-12/45 airplanes. This proposal was published in the Federal Register as a notice of proposed rulemaking (NPRM) on March 1, 2002 (67 FR 9420). The NPRM proposed to require you to inspect the left and right main landing gear (MLG) assemblies for bolts with a serial number (S/N) beginning with the letters "AT" and numbers 299 or lower and replace each bolt with a bolt that does not have a S/N with both the letters "AT" and a number of 299 or lower.

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?

After careful review of all available information related to the subject presented above, we have determined that air safety and the public interest require the adoption of the rule as proposed except for minor editorial corrections. We have determined that these 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 16 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 inspection and replacement:

Labor cost
Parts cost
Total cost per airplane
Total cost on U.S. operators
Manufacturer will pay for workhours
Parts will be provided at no cost to the owners/operators of the affected aircraft.
None
None.

Compliance Time of This AD

What Will Be the Compliance Time of This AD?The compliance time of this AD is "within the next 30 days after the effective date of this AD".

Why Is the Compliance Time Presented in Calendar Time Instead of Hours Time-in-service (TIS)?

Although malfunction of the main landing gear is unsafe during flight, the condition is not a direct result of airplane operation. The chance of this situation occurring is the same for an airplane with 10 hours TIS as it would be for an airplane with 500 hours TIS. A calendar time for compliance will ensure that the unsafe condition is addressed on all airplanes in a reasonable time period.

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.

Sec. 39.13 [Amended]

2. FAA amends Sec. 39.13 by adding a new AD to read as follows: