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Proposed Rule

Airworthiness Directives; Pilatus Aircraft Ltd. Models PC-12 and PC-12/45 Airplanes

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Information about this document as published in the Federal Register.

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AGENCY:

Federal Aviation Administration (FAA), DOT.

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ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to adopt a new airworthiness directive (AD) for all Pilatus Aircraft Ltd. (Pilatus) Models PC-12 and PC-12/45 airplanes. This proposed AD would require you to determine whether certain main landing gear shock absorber attachment bolts have been replaced and, if not replaced would require you to replace shock absorber attachment bolts on main landing gear assemblies that had a serial number beginning with AM. This proposed AD is the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for Switzerland. We are issuing this proposed AD to detect and correct hydrogen embrittlement in the main landing gear shock absorber attachment bolts, which could result in failure of the main landing gear. This failure could lead to main landing gear collapse during operation with consequent loss of airplane control.

DATES:

We must receive any comments on this proposed AD by February 19, 2004.

ADDRESSES:

Use one of the following to submit comments on this proposed AD:

  • By mail: FAA, Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 2003-CE-55-AD, 901 Locust, Room 506, Kansas City, Missouri 64106.
  • By fax: (816) 329-3771.
  • By e-mail: 9-ACE-7-Docket@faa.gov. Comments sent electronically must contain “Docket No. 2003-CE-55-AD” in the subject line. If you send comments electronically as attached electronic files, the files must be formatted in Microsoft Word 97 for Windows or ASCII.

You may get the service information identified in this proposed AD 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 the AD docket at FAA, Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 2003-CE-55-AD, 901 Locust, Room 506, Kansas City, Missouri 64106. Office hours are 8 a.m. to 4 p.m., Monday through Friday, except Federal holidays.

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FOR FURTHER INFORMATION 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.

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SUPPLEMENTARY INFORMATION:

Comments Invited

How do I comment on this proposed AD? We invite you to submit any written relevant data, views, or arguments regarding this proposal. Send your comments to an address listed under ADDRESSES. Include “AD Docket No. 2003-CE-55-AD” in the subject line of your comments. If you want us to acknowledge receipt of your mailed comments, send us a self-addressed, stamped postcard with the docket number written on it. We will date-stamp your postcard and mail it back to you.

Are there any specific portions of this proposed AD I should pay attention to? We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this proposed AD. If you contact us through a nonwritten communication and that contact relates to a substantive part of this proposed AD, we will summarize the contact and place the summary in the docket. We will consider all comments received by the closing date and may amend this proposed AD in light of those comments and contacts.

Discussion

What events have caused this proposed 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 Pilatus Models PC-12 and PC-12/45 airplanes. The FOCA reports that certain shock absorber attachment bolts (part number 532.10.12.110) in the main landing gear assemblies could fail during operation. Investigations revealed that an improper cadmium plating process applied to the high strength steel part causes the problem. This can cause hydrogen embrittlement.

The only bolts affected are those installed on main landing gear assemblies with a serial number that starts with AM.

What are the consequences if the condition is not corrected? Failure of the main landing gear could lead to main landing gear collapse during operation with consequent loss of airplane control.

Is there service information that applies to this subject? Pilatus has issued PC12 Service Bulletin No. 32-015, dated September 12, 2003.

What are the provisions of this service information? The service bulletin includes procedures for:

—Inspecting the left and right main landing gear assemblies if the assemblies have a serial number beginning with AM; and

—Replacing the shock absorber attachment bolts if any main landing gear assembly has a serial number beginning with AM.

What action did the FOCA take? The FOCA classified this service bulletin as mandatory and issued Swiss AD Number HB 2003-522, dated November 14, 2003, to ensure the continued airworthiness of these airplanes in Switzerland.

Did the FOCA inform the United States under the bilateral airworthiness agreement? These Pilatus Models PC-12 and PC-12/45 airplanes are manufactured in Switzerland and are type-certificated for operation in the United States under the provisions of section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral airworthiness agreement.

Under this bilateral airworthiness agreement, the FOCA has kept us informed of the situation described above.

FAA's Determination and Requirements of This Proposed AD

What has FAA decided? We have examined the FOCA's findings, reviewed all available information, and determined that AD action is necessary for products of this type design that are certificated for operation in the United States.

Since the unsafe condition described previously is likely to exist or develop on other Pilatus Models PC-12 and PC-12/45 airplanes of the same type design that are registered in the United States, we are proposing AD action to detect and correct hydrogen embrittlement in the main landing gear shock absorber attachment bolts, which could result in failure of the main landing gear.

What would this proposed AD require? This proposed AD would require you to determine whether certain main landing gear shock absorber attachment bolts have been replaced and, if not replaced would require you to replace shock absorber attachment bolts on main landing gear assemblies that had a serial number beginning with AM.

How does the revision to 14 CFR part 39 affect this proposed AD? On July 10, 2002, we published a new version of 14 CFR part 39 (67 FR 47997, July 22, 2002), which governs FAA's AD system. This regulation now includes material that relates to altered products, special flight permits, and alternative methods of compliance. This material previously Start Printed Page 1553was included in each individual AD. Since this material is included in 14 CFR part 39, we will not include it in future AD actions.

Costs of Compliance

How many airplanes would this proposed AD impact? We estimate that this proposed AD affects 260 airplanes in the U.S. registry.

What would be the cost impact of this proposed AD on owners/operators of the affected airplanes? The manufacturer will provide parts free of charge and will pay for the estimated 3 workhours required to do the inspection and replacement of the shock absorber attachment bolts.

Compliance Time of This Proposed AD

What would be the compliance time of this proposed AD? The compliance time of this proposed AD is within the next 30 calendar days after the effective date of this AD.

Why is this proposed compliance time presented in calendar time instead of hours time-in-service (TIS)? The unsafe condition exists or could develop on airplanes equipped with the affected parts regardless of airplane operation. For example, the unsafe condition has the same chance of occurring on an airplane with 50 hours TIS as it does on one with 5,000 hours TIS. Therefore, we are presenting the compliance time of the proposed AD in calendar time instead of hours TIS.

Regulatory Findings

Would this proposed AD impact various entities? We have determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would 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.

Would this proposed AD involve a significant rule or regulatory action? For the reasons discussed above, I certify that this proposed AD:

1. Is not a “significant regulatory action” under Executive Order 12866;

2. Is not a “significant rule” under the 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.

We prepared a summary of the costs to comply with this proposed AD and placed it in the AD Docket. You may get a copy of this summary by sending a request to us at the address listed under ADDRESSES. Include “AD Docket No. 2003-CE-55-AD” in your request.

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List of Subjects in 14 CFR Part 39

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The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend 14 CFR part 39 as follows:

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PART 39—AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

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Authority: 49 U.S.C. 106(g), 40113, 44701.

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[Amended]

2. The FAA amends § 39.13 by adding the following new airworthiness directive (AD):

Pilatus Aircraft Ltd.: Docket No. 2003-CE-55-AD.

When Is the Last Date I Can Submit Comments on This Proposed AD?

(a) We must receive comments on this proposed airworthiness directive (AD) by February 19, 2004.

What Other ADs Are Affected by This Action?

(b) None.

What Airplanes Are Affected by This AD?

(c) This AD affects Models PC-12 and PC-12/45 airplanes, all serial numbers, that are certificated in any category.

What Is the Unsafe Condition Presented in This AD?

(d) This AD is the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for Switzerland. The actions specified in this AD are intended to detect and correct hydrogen embrittlement in the main landing gear shock absorber attachment bolts, which could result in failure of the main landing gear. This failure could lead to main landing gear collapse during operation with consequent loss of airplane control.

What Must I Do To Address This Problem?

(e) To address this problem, you must do the following:

ActionsComplianceProcedures
(1) Maintenance Records Check: (i) Check the maintenance records to determine whether the main landing gear (MLG) shock absorber attachment bolts (part number (P/N) 532.10.12.110) have been replaced. The bolts must have been replaced by following Pilatus PC12 Service Bulletin No: 32-015, dated September 12, 2003. The owner/operator holding at least a private pilot certificate as authorized by section 43.7 of the Federal Aviation Regulations (14 CFR 43.7) may perform this check. (ii) If, by checking the maintenance records, the owner/operator can definitely show that the MLG gear shock absorber attachment bolts (P/N 532.10.12.110) have been replaced (by following Pilatus PC12 Service Bulletin No: 32-015, dated September 12, 2003), then report the removal of any bolts to FAA at the address in paragraph (f) of this AD. You must make an entry into the aircraft records that shows compliance with this portion of the AD in accordance with section 43.9 of the Federal Aviation Regulations (14 CFR 43.9).Within the next 30 calendar days after the effective date of this AD, unless already done.No special procedures necessary to check the maintenance records.
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(2) If you find as a result of the check in paragraph (e)(1) that there is no record of bolt replacement, inspect the left and right MLG assemblies (P/N 532.10.12.049 and P/N 532.10.12.050) for any serial number beginning with AM. You may choose to do the inspection without doing the logbook check.Within the next 30 calendar days after the effective date of this AD, unless already done.Follow the Accomplishment Instructions of Pilatus PC12 Service Bulletin No: 32-015, dated September 12, 2003.
(3) If during the inspection required by paragraph (e)(2) of this AD, you find any MLG assembly with a serial number beginning with AM, replace the shock absorber bolts (P/N 532.10.12.110) with new bolts.Before further flight after the inspection required by paragraph (e)(2) of this AD.Follow the Accomplishment Instructions of Pilatus PC12 Service Bulletin No: 32-015, dated September 12, 2003.
(4) After removal of the shock absorber bolts (P/N 532.10.12.110), send the old removed bolts to Pilatus. Report this to FAA at the address in paragraph (f) of this AD.Within the next 30 calendar days after the effective date of this AD, unless already done.Not Applicable.
(5) Before installing any left or right MLG assembly (P/N 532.10.12.049 or P/N 532.10.12.050) that has a serial number beginning with AM, ensure that the shock absorber bolts (P/N 532.10.12.110) have been replaced, and, if not, replace with new bolts.As of the effective date of this AD.Not Applicable.

May I Request an Alternative Method of Compliance?

(f) You may request a different method of compliance or a different compliance time for this AD by following the procedures in 14 CFR 39.13. Send your request to the Manager, Standards Office, Small Airplane Directorate, FAA. For information on 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.

May I Get Copies of the Documents Referenced in This AD?

(g) You may get copies of the documents referenced in this AD 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 these documents at FAA, Central Region, Office of the Regional Counsel, 901 Locust, Room 506, Kansas City, Missouri 64106.

Is There Other Information That Relates to This Subject?

(h) Swiss AD Number HB 2003-522, dated November 14, 2003, also addresses the subject of this AD.

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Issued in Kansas City, Missouri, on January 2, 2004.

David R. Showers,

Acting Manager, Small Airplane Directorate, Aircraft Certification Service.

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[FR Doc. 04-476 Filed 1-8-04; 8:45 am]

BILLING CODE 4910-13-P