E6-5978. Airworthiness Directives; Pilatus Aircraft Ltd. Models PC-6, PC-6-H1, PC-6-H2, PC-6/350, PC-6/350-H1, PC-6/350-H2, PC-6/A, PC-6/A-H1, PC-6/A-H2, PC-6/B-H2, PC-6/B1-H2, PC-6/B2-H2, PC-6/B2-H4, PC-6/C-H2, and PC-6/C1-H2 Airplanes

AGENCY:

Federal Aviation Administration (FAA), Department of Transportation (DOT).

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

We propose to supersede Airworthiness Directive (AD) 98-12-01, which applies to certain Pilatus Aircraft Ltd (Pilatus) Models PC-6, PC-6/A, PC-6/B, and PC-6/C series airplanes equipped with turbo-prop engines. AD 98-12-01 currently requires you to modify the fuel system to improve the venting between the collector tank, the main wing tanks, and the engine. Since we issued AD 98-12-01, the FAA determined the action should also apply to all the models of the PC-6 airplanes listed in the type certification data sheet of Type Certificate (TC) No. 7A15 that are produced in the United States through a licensing agreement between Pilatus and Fairchild Republic Company (also identified as Fairchild Industries, Fairchild Heli Porter, or Fairchild-Hiller Corporation). In addition, the intent of the applicability of AD 98-12-01 was to apply to affected serial numbers of the airplane models listed in TC No. 7A15. Consequently, this proposed AD would retain all the actions of AD 98-12-01, would add those Fairchild Republic Company airplanes to the applicability of this proposed AD, and would list out the individual specific airplane models. We are proposing this AD to prevent engine fuel starvation during maximum climb and descent caused by poor fuel tank venting with low fuel levels, which could result in a loss of engine power during critical phases of flight.

DATES:

We must receive comments on this proposed AD by May 24, 2006.

ADDRESSES:

Use one of the following addresses to comment on this proposed AD:

• DOT Docket Web site: Go to http://dms.dot.gov and follow the instructions for sending your comments electronically.
• Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your comments electronically.
• Mail: Docket Management Facility; U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, Washington, DC 20590-0001.
• Fax: [phone].
• Hand Delivery: Room PL-401 on the plaza level of the Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

For service information identified in this proposed AD, contact Pilatus Aircraft Ltd., Customer Liaison Manager, CH-6371 Stans, Switzerland; telephone: [phone]; facsimile: [phone].

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

We invite you to send any written relevant data, views, or arguments regarding this proposed AD. Send your comments to an address listed under the ADDRESSES section. Include the docket number, “FAA-2006-24091; Directorate Identifier 2006-CE-17-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. We will consider all comments received by the closing date and may amend the proposed AD in light of those comments.

We will post all comments we receive, without change, to http://dms.dot.gov,, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive concerning this proposed AD.

Discussion

Mandatory continuing airworthiness information and the FAA's determination that an unsafe condition existed on certain Pilatus Models PC-6, PC-6/A, PC-6/B-H2, PC-6/B1-H2, PC-6/B, PC-6/C series airplanes (all models in the TCDS) equipped with turbo-prop engines caused us to issue AD 98-12-01, Amendment 39-10558 (63 FR 30370, June 4, 1998). AD 98-12-01 currently requires you to modify the fuel system to improve the venting between the collector tank, the main wing tanks, and the engine on certain Models PC-6, PC-6/A, PC-6/B-H2, PC-6/B1-H2, PC-6/B, PC-6/C series airplanes.

The Federal Office for Civil Aviation (FOCA), which is the airworthiness authority for Switzerland, notified the FAA of the need to supersede AD 98-12-01 to address an unsafe condition that may exist or could develop on certain Models PC-6, PC-6/A, PC-6/B-H2, PC-6/B1-H2, PC-6/B, PC-6/C series airplanes. The FOCA reports that the AD action should also apply to all the models of the PC-6 airplanes listed in the type certification data sheet of TC No. 7A15 produced in the United States through a licensing agreement between Pilatus and Fairchild Republic Company (also identified as Fairchild Industries, Fairchild Heli Porter, or Fairchild-Hiller Corporation).

This condition, if not corrected, could result in engine fuel starvation during maximum climb and descent caused by poor fuel tank venting with low fuel levels, which could result in a loss of engine power during critical phases of flight.

Foreign Airworthiness Authority Information

The FOCA recently issued Swiss AD Number HB 2005-289, effective date August 23, 2005, to ensure the continued airworthiness of all models of the PC-6 airplanes listed in TC No. 7A15, including those produced in the United States under a licensing agreement with Pilatus and Fairchild Republic Company (also identified as Fairchild Industries, Fairchild Heli Porter, or Fairchild-Hiller Corporation).

The State of Design for the Pilatus PC-6 airplanes is Switzerland and the airplanes 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 the Proposed AD

We are proposing this AD because we have examined the FOCA's findings, evaluated all information and determined the unsafe condition described previously is likely to exist or develop on other products of the same type design that are certificated for operation in the United States.

This proposed AD would supersede AD 98-12-01 with a new AD that would retain all the actions of AD 98-12-01 and would:

• Add manufacturer serial numbers (MSN) 2001 through 2092 for all the models of the PC-6 airplanes as listed in TC No. 7A15 and specified in the applicability section. These MSN are the airplanes produced in the United States through a licensing agreement with the Fairchild Republic Company; and
• List all the models of the PC-6 airplanes as listed in TC No. 7A15.

Costs of Compliance

We estimate that this proposed AD would affect 43 airplanes in the U.S. registry.

We estimate the following costs to do the proposed modification of the fuel system to improve venting between the collector tank, the main wing tanks, and the engine:

Labor cost	Parts cost	Total cost per airplane	Total cost on U.S. operators
10 work hours × $80 per hour = $800	$614	$1,414	$1,414 × 43 = $60,802.

Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the Agency's authority.

We are issuing this rulemaking under the authority described in subtitle VII, part A, subpart III, section 44701, “General requirements.” Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.

Regulatory Findings

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.

For the reasons discussed above, I certify that the proposed regulation:

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 regulatory evaluation of the estimated costs to comply with this proposed AD and placed it in the AD docket.

Examining the AD Docket

You may examine the AD docket that contains the proposed AD, the regulatory evaluation, any comments received, and other information on the Internet at http://dms.dot.gov;​; or in person at the Docket Management Facility between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Office (telephone [phone]) is located at the street address stated in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

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 FAA 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 removing Airworthiness Directive (AD) 98-12-01, Amendment 39-10558, and adding the following new AD:

Pilatus Aircraft Ltd.: Docket No. FAA-2006-24091; Directorate Identifier 2006-CE-17-AD.

Comments Due Date

(a) We must receive comments on this proposed airworthiness directive (AD) action by May 24, 2006.

Affected ADs

(b) This AD supersedes AD 98-12-01, Amendment 39-10558.

Applicability

(c) This AD affects the following Models PC-6, PC-6-H1, PC-6-H2, PC-6/350, PC-6/350-H1, PC-6/350-H2, PC-6/A, PC-6/A-H1, PC-6/A-H2, PC-6/B-H2, PC-6/B1-H2, PC-6/B2-H2, PC-6/B2-H4, PC-6/C-H2, and PC-6/C1-H2 airplanes that are equipped with turbo-prop engines and certificated in any category:

(1) Group 1 (maintains the actions from AD 98-12-01): All manufacturer serial numbers (MSN) up to and including 915.

(2) Group 2: MSN 2001 through 2092.

Note:

These airplanes are also identified as Fairchild Republic Company PC-6 airplanes, Fairchild Heli Porter PC-6 airplanes, or Fairchild-Hiller Corporation PC-6 airplanes.

Unsafe Condition

(d) This AD results from mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for Switzerland that requires the actions of AD 98-12-01 for the added MSN 2001 through 2092 for all the models of the PC-6 airplanes listed in the type certificate data sheet of Type Certificate (TC) No. 7A15. We are issuing this AD to prevent engine fuel starvation during maximum climb and descent caused by poor fuel tank venting with low fuel levels, which could result in a loss of engine power during critical phases of flight.

Compliance

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

Actions	Compliance	Procedures
(1) Modify the fuel system to improve the venting between the collector tank, the main wing tanks, and the engine	(i) For Group 1 Airplanes: Within the next 3 calendar months after July 13, 1998 (the effective date of AD 98-12-01), unless already done	Follow Pilatus PC-6 Service Bulletin No. PC-6-SB-171, dated October 18, 1995.
	(ii) For Group 2 Airplanes: Within the next 3 calendar months after the effective date of this AD, unless already done
(2) Do not install any collector tank or fuel vent system unless the modification requirements of paragraph (e)(1) are done	For all airplanes: As of the effective date of this AD	Follow Pilatus PC-6 Service Bulletin No. PC-6-SB-171, dated October 18, 1995.

Alternative Methods of Compliance (AMOCs)

(f) The Manager, Standards Office, ATTN: Doug Rudolph, Aerospace Engineer, FAA, Small Airplane Directorate, 901 Locust, Room 301, Kansas City, Missouri 64106; telephone: [phone]; facsimile: [phone], has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19.

(g) AMOCs approved for AD 98-12-01 are approved for this AD.

Related Information

(h) Swiss AD Number HB 2005-289, effective date August 23, 2005, also addresses the subject of this AD. To get copies of the documents referenced in this AD, contact Pilatus Aircraft Ltd., Customer Liaison Manager, CH-6371 Stans, Switzerland; telephone: [phone]; facsimile: [phone]. To view the AD docket, go to the Docket Management Facility; U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, Washington, DC, or on the Internet at http://dms.dot.gov. The docket number is Docket No. FAA-2006-24091; Directorate Identifier 2006-CE-17-AD.

Issued in Kansas City, Missouri, on April 17, 2006.

John Colomy,

Acting Manager, Small Airplane Directorate, Aircraft Certification Service.