04-8054. Airworthiness Directives; Pilatus Aircraft Ltd. Models PC-12 and PC-12/45 Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

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 check the airplane logbook to determine whether certain inboard and outboard flap flexshafts have been replaced with parts of improved design. If the parts of improved design are not installed, you would be required to replace certain inboard and/or outboard flap flexshafts with the parts of improved design. The pilot is allowed to do the logbook check. If the pilot can positively determine that the parts of improved design are installed, no further action is required. 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 prevent rupture of the flap flexshafts due to corrosion, which could result in failure of the flap system. This failure could lead to loss of control of the airplane.

DATES:

We must receive any comments on this proposed AD by May 7, 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. 2004-CE-08-AD, 901 Locust, Room 506, Kansas City, Missouri 64106.
• By fax: [phone].
• By e-mail: [e-mail]. Comments sent electronically must contain “Docket No. 2004-CE-08-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: [phone]; facsimile: [phone]; e-mail: [e-mail] or from Pilatus Business Aircraft Ltd., Product Support Department, 11755 Airport Way, Broomfield, Colorado 80021; telephone: [phone]; facsimile: [phone].

You may view the AD docket at FAA, Central Region, Office of the Regional Counsel, Attention: Rules Docket No. 2004-CE-08-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.

FOR FURTHER INFORMATION CONTACT:

Doug Rudolph, Aerospace Engineer, FAA, Small Airplane Directorate, 901 Locust, Room 301, Kansas City, Missouri 64106; telephone: [phone]; facsimile: [phone].

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. 2004-CE-08-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 all Pilatus Models PC-12 and PC-12/45 airplanes equipped with an inboard and/or outboard flap flexshaft, part numbers (P/N) 945.02.02.203 and/or 945.02.02.204. The FOCA reports several occurrences of corrosion found on the inner drive cables of these flap flexshafts.

The FOCA determined that moisture from the pressurized cabin could enter the flap flexshafts through the fittings of the protection hose causing corrosion. This corrosion could cause the flap flexshafts to rupture.

What Are the Consequences if the Condition Is Not Corrected?

If not prevented, corrosion on the flap flexshafts could cause the flap system to fail. This failure could result in loss of control of the airplane.

Is There Service Information That Applies to This Subject?

Pilatus has issued Pilatus PC12 Service Bulletin No. 27-015, Rev. No. A, dated November 13, 2003.

What Are the Provisions of This Service Information?

The service bulletin includes procedures for replacing the inboard and outboard flap flexshafts, P/N 945.02.02.203 and P/N 945.02.02.204, with parts of improved design, P/N 945.02.02.205 and P/N 945.02.02.206.

What Action Did the FOCA Take?

The FOCA classified this service bulletin as mandatory and issued Swiss AD Number HB-2004-068, dated March 4, 2004, 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 equipped with an inboard and/or outboard flap flexshaft, P/N 945.02.02.203 and/or P/N 945.02.02.204, and are registered in the United States, we are proposing AD action to prevent failure of the flap system.

What Would This Proposed AD Require?

This proposed AD would require you to incorporate the actions in the previously-referenced service bulletin.

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 was 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?

We estimate the following costs to accomplish this proposed replacement:

Labor cost per flap flexshaft	Parts cost per flap flexshaft	Total cost per airplane per flap flexshaft	Total cost on U.S. operators
2 workhours per flap flexshaft (4 flap flexshafts per airplane) × $65 per hour = $130 per flap flexshaft	$750 per flap flexshaft (4 flap flexshafts per airplane)	$130 + $750 = $880 per flap flexshaft. $880 × 4 flap flexshafts = $3,520 to replace all 4 flap flexshafts	Maximum cost for replacing all 4 flap flexshafts on all 260 airplanes = $3,520 × 260 = $915,200.

Compliance Time of This Proposed AD

What Would Be the Compliance Time of This Proposed AD?

The compliance time of the proposed replacement that would be required by this proposed AD is “within the next 30 days after the effective date of this AD.”

Why Is This Proposed Compliance Time Presented in Calendar Time Instead of Hours TIS?

The unsafe condition specified by this proposed AD is caused by corrosion. Corrosion can occur regardless of whether the airplane is in operation or is in storage. Therefore, to assure that the unsafe condition specified in this proposed AD does not go undetected for a long period of time, a compliance time of calendar time is utilized.

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. 2004-CE-08-AD” in your request.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

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:

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

Pilatus Aircraft Ltd.: Docket No. 2004-CE-08-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 May 7, 2004.

What Other ADs Are Affected by This Action?

(b) None.

What Airplanes Are Affected by This AD?

(c) This AD affects Model PC-12 and PC-12/45 airplanes, all serial numbers, that are:

(1) equipped with an inboard and/or outboard flap flexshaft, part number (P/N) 945.02.02.203 and/or P/N 945.02.02.204; and

(2) 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 prevent rupture of the flap flexshafts due to corrosion, which could result in failure of the flap system. This failure could lead to loss of control of the airplane.

What Must I Do To Address This Problem?

(e) To address this problem, you must do the following. If you already replaced both the inboard and outboard flap flexshafts with P/N 945.02.02.205 and P/N 945.02.02.206 following Pilatus PC12 Service Bulletin No. 27-015, dated June 4, 2003, then paragraph (e)(5) of this AD is the only paragraph that applies to you:

Actions	Compliance	Procedures
(1) For affected airplanes with a manufacturer serial number (MSN) of 489 or lower, check the airplane logbook to determine if the inboard and outboard flap flexshafts have been replaced with P/N 945.02.02.205 and P/N 945.02.02.206	Within the next 30 days after the effective date of this AD	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.
(2) For affected airplanes with a MSN of 490 and above, check the airplane logbook to determine if the inboard and outboard flap flexshafts, P/N 945.02.02.205 and P/N 945.02.02.206 have been replaced since delivery	Within the next 30 days after the effective date of this AD	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.
(3) If you can positively determine that both inboard and outboard flap flexshafts, P/Ns 945.02.02.205 and 945.02.02.206 are installed, no replacement is required	Not applicable	Not applicable.
(4) If you cannot positively determine that both inboard and outboard flap flexshafts, P/N 945.02.02.205 and P/N 945.02.02.206 are installed, you must replace either one or both with P/N 945.02.02.205 and P/N 945.02.02.206, as applicable	Before further flight after the logbook checks required in paragraph (e)(1) and (e)(2) of this AD	Follow Pilatus PC12 Service Bulletin No. 27-015 as specified in paragraph (f) of this AD.
(5) Install only inboard and outboard flap flexshafts, P/Ns 945.02.02.205 and 945.02.02.206	As of the effective date of this AD	Not applicable.

What Revision Levels do the Affected Service Bulletin Incorporate?

(f) The service bulletin required to do the actions required in this AD incorporate the following pages:

Affected pages	Revision level	Date
1 and 2	A	November 13, 2003.
3 through 11	Original Issue	June 4, 2003.

May I Request an Alternative Method of Compliance?

(g) You may request a different method of compliance or a different compliance time for this AD by following the procedures in 14 CFR 39.19. Unless FAA authorizes otherwise, send your request to your principal inspector. The principal inspector may add comments and will 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: [phone]; facsimile: [phone].

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

(h) You may get copies of the documents referenced in this AD from Pilatus Aircraft Ltd., Customer Liaison Manager, CH-6371 Stans, Switzerland; telephone: [phone]; facsimile: [phone]; e-mail: [e-mail] or from Pilatus Business Aircraft Ltd., Product Support Department, 11755 Airport Way, Broomfield, Colorado 80021; telephone: [phone]; facsimile: [phone]. 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?

(i) Swiss AD Number HB-2004-068, dated March 4, 2004, also addresses the subject of this AD.

Issued in Kansas City, on April 1, 2004.

David R. Showers,

Acting Manager, Small Airplane Directorate, Aircraft Certification Service.