03-15224. Airworthiness Directives; Pratt & Whitney Canada PT6A-60A and PT6A-65B Turboprop Engines

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to adopt a new airworthiness directive (AD) for Pratt & Whitney Canada (PWC) PT6A-60A and PT6A-65B turboprop engines. This proposed AD would require replacing Woodward propeller governor assemblies, part number (P/N) 8210-212H. This proposed AD is prompted by six incidents during airplane acceptance flight testing where directional control of the airplane was difficult to maintain during landing. The actions specified in this proposed AD are intended to prevent loss of directional control and damage to the airplane.

DATES:

We must receive any comments on this proposed AD by August 18, 2003.

ADDRESSES:

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

• By mail: Federal Aviation Administration (FAA), New England Region, Office of the Regional Counsel, Attention: Rules Docket No. 2003-NE-09-AD, 12 New England Executive Park, Burlington, MA 01803-5299.
• By fax: [phone].
• By e-mail: [e-mail].

You may get the service information identified in this proposed AD from Pratt & Whitney Canada, 1000 Marie-Victorin, Longueuil, Quebec, Canada J4G1A1.

You may examine the AD docket at the FAA, New England Region, Office of the Regional Counsel, 12 New England Executive Park, Burlington, MA.

FOR FURTHER INFORMATION CONTACT:

Ian Dargin, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803-5299; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

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-NE-09-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. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. If a person contacts 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 the proposed AD in light of those comments.

We are reviewing the writing style we currently use in regulatory documents. We are interested in your comments on whether the style of this document is clear, and your suggestions to improve the clarity of our communications that affect you. You may get more information about plain language at http://www.plainlanguage.gov.

Examining the AD Docket

You may examine the AD Docket (including any comments and service information), by appointment, between 8 a.m. and 4:30 p.m., Monday through Friday, except Federal holidays. See ADDRESSES for the location.

Discussion

Transport Canada, which is the airworthiness authority for Canada, recently notified the FAA that an unsafe condition may exist on PWC PT6A-60A and PT6A-65B turbofan engines. Transport Canada advises the FAA that there have been six reports from the airplane manufacturer that it was difficult to maintain directional control of the airplane during landing. These events were reported to have occurred during airplane acceptance flight testing. Certain governors that incorporate propeller control units (PCUs) with thicker O-rings on the Beta valve shafts of the PCUs may not set the appropriate ground idle blade angle when the airplane lands. If this happens on one engine only, a substantial and unexpected asymmetric thrust condition will occur.

The introduction of a thicker O-ring on the Beta valve shaft of the PCU addressed a nuisance oil leakage issue. A side effect of fitting this thicker O-ring is that a slightly higher input force is required to move the Beta valve to the ground idle position. On the installations using the PT6A-60A and PT6A-65B engines, the airframe installations have a solenoid system that relies on the force of an internal spring within the Beta valve to move the valve to the ground idle command position. The force of this spring is insufficient to overcome the increased friction of the thicker O-ring and ensure that the valve consistently and promptly moves to the ground idle position. As a result, the pilot may experience directional control problems during landing. There have been no reports of in-service incidents to date. The actions specified in this proposed AD are intended to prevent loss of directional control and damage to the airplane.

This proposed AD is not applicable to engine models operating with the Woodward propeller governor, P/N 8210-212J, since they operate with a push-pull rod mechanism to move the Beta valve. That arrangement provides ample force to overcome the O-ring's frictional resistance.

Relevant Service Information

PWC has issued Service Bulletin (SB) PT6A-72-13354, dated July 6, 2001. That SB provides information for the removal, replacement, or modification of Woodward propeller governor assembly, P/N 8210-212H. Transport Canada classified this SB as mandatory and issued airworthiness directive CF-2002-02, dated January 15, 2002, in order to ensure the airworthiness of these PWC engines in Canada.

Differences Between This Proposed AD and the Manufacturer's Service Information

Although the SB recommends the removal, replacement or modification of Woodward propeller governor assemblies, P/N 8210-212H, when the engine is disassembled and access is available to the necessary subassembly (i.e. module, accessories, components, or build groups), this proposed AD would require compliance at the next access or within six months after the effective date of this AD, whichever occurs first.

FAA's Determination and Requirements of the Proposed AD

These PT6A-60A and PT6A-65B engine models, manufactured in Canada, 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. Pursuant to this bilateral airworthiness agreement, Transport Canada has kept us informed of the situation described above. We have examined Transport Canada'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. Therefore, we are proposing this AD, which would require replacing Woodward propeller governor assemblies, P/N 8210-212H.

Changes to 14 CFR Part 39—Effect on the Proposed AD

On July 10, 2002, we published a new version of 14 CFR part 39 (67 FR 47997, July 22, 2002), which governs the 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

There are approximately 73 Pratt & Whitney Canada PT6A-60A and PT6A-65B turboprop engines of the affected design in the worldwide fleet. We estimate that 70 engines installed on airplanes of U.S. registry would be affected by this proposed AD. We also estimate that it would take approximately 2 work hours per engine to perform the proposed actions, and that the average labor rate is $60 per work hour. Required parts would cost approximately $24,228 per engine. Based on these figures, the total cost of the proposed AD to U.S. operators is estimated to be $1,704,360. PWC has informed the FAA that it may provide the parts and labor to the operators at no cost, thereby substantially reducing the cost impact of this proposed rule.

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. Would 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 proposal 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-NE-09-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:

Pratt and Whitney Canada: Docket No. 2003-NE-09-AD.

Comments Due Date: (a) The Federal Aviation Administration (FAA) must receive comments on this airworthiness directive (AD) action by August 18, 2003.

Affected ADs: (b) None.

Applicability: (c) This AD is applicable to Pratt & Whitney Canada (PWC) PT6A-60A and PT6A-65B turboprop engines that have Woodward propeller governor assemblies, part number, (P/N) 8210-212H, installed. These engines are installed on, but not limited to, Raytheon Super Beech King Air 300/350 and Raytheon Beech 1900/1900C airplanes.

Unsafe Condition: (d) This AD was prompted by six incidents during airplane acceptance flight testing, whereby directional control of the airplane was difficult to maintain during landing. The actions specified in this AD are intended to prevent loss of directional control and damage to the airplane.

Compliance: (e) Compliance with this AD is required as indicated, unless already done.

Removal of Woodward Propeller Governor Assemblies

(f) Replace Woodward propeller governor assemblies, P/N 8210-212H, at the next access to the governor or within six months after the effective date of this AD, whichever occurs earlier. Information on replacing the Woodward propeller governor assembly can be found in Pratt & Whitney Canada Service Bulletin PT6A-72-13354, dated July 6, 2001.

(g) After the effective date of this AD, do not install any Woodward propeller governor assembly, P/N 8210-212H, on any engine.

Alternative Methods of Compliance

(h) Alternative methods of compliance must be requested in accordance with 14 CFR part 39.19, and must be approved by the Manager, Engine Certification Office, FAA.

Material Incorporated by Reference

(i) None

Related Information

(j) The subject of this AD is addressed in Transport Canada airworthiness directive CF-2002-02, dated January 15, 2002.

Issued in Burlington, Massachusetts, on June 9, 2003.

Francis A. Favara,

Acting Manager, Engine and Propeller Directorate, Aircraft Certification Service.