03-30587. Airworthiness Directives; Pratt & Whitney Canada Models PW123, PW123B, PW123C, PW123D, PW123E, PW123AF, PW124B, PW125B, PW126A, PW127, PW127E, PW127F, and PW127G 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) models PW123, PW123B, PW123C, PW123D, PW123E, PW123AF, PW124B, PW125B, PW126A, PW127, PW127E, PW127F, and PW127G turboprop engines. This proposed AD would require initial and repetitive gap inspections of the bypass valve cover, on certain part number (P/N) mechanical fuel controls (MFCs), and replacement of those MFCs as mandatory terminating action to the repetitive inspections. This proposed AD is prompted by sixteen reports of loss of engine throttle response and overspeed, eight of which resulted in in-flight shutdown. We are proposing this AD to prevent loss of throttle response and overspeed, resulting in engine in-flight shutdown.

DATES:

We must receive any comments on this proposed AD by February 9, 2004.

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-35-AD, 12 New England Executive Park, Burlington, MA 01803-5299.
• By fax: [phone].
• By e-mail: [e-mail].

You can get the service information identified in this proposed AD from Honeywell Engines & Systems, Technical Publications Department, 111 South 34th Street, Phoenix, Arizona 85034; telephone [phone]; fax [phone].

You may examine the AD docket, by appointment, 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-35-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 verbally, 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.faa.gov/​language and 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 models PW123, PW123B, PW123C, PW123D, PW123E, PW123AF, PW124B, PW125B, PW126A, PW127, PW127E, PW127F, and PW127G turboprop engines. Transport Canada advises that sixteen reports of loss of engine throttle response and overspeed have been received, eight of which resulted in in-flight shutdown. Investigation by the manufacturer revealed that the cause of this problem is dislodgement of the outer lip of the mechanical fuel control bypass valve diaphragm. The dislodgement is caused by inadequate preload applied to the bypass valve diaphragm outer lip during the assembly of the MFC.

Relevant Service Information

We have reviewed and approved the technical contents of Honeywell Service Information Bulletin (SIB) No. 82, dated September 14, 2001, that describes procedures for detecting dislodgement of the outer lip of the MFC bypass valve diaphragm, by performing gap inspections of the bypass valve cover on affected MFCs.

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

Although Honeywell SIB No. 82, dated September 14, 2001, suggests the gap inspections be done periodically at the aircraft “A” check, this proposal requires initial gap inspections within 500 hours time-in-service (TIS) after the effective date of the proposed AD, and repetitive gap inspections at intervals of 1,500 hours TIS. This proposal also requires replacement of the MFC with an MFC that has an improved design bypass valve diaphragm.

FAA's Determination and Requirements of the Proposed AD

These PWC models PW123, PW123B, PW123C, PW123D, PW123E, PW123AF, PW124B, PW125B, PW126A, PW127, PW127E, PW127F, and PW127G turboprop engines, 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:

• Initial gap inspection of the bypass valve cover on affected MFCs, within 500 hours time-in-service (TIS) after the effective date of the proposed AD.
• Repetitive gap inspections of the bypass valve cover on affected MFCs, at intervals of 1,500 hours TIS.
• Replacement of the affected MFC with an MFC that has an improved design bypass valve diaphragm, within 4,500 hours-in-service or 24 months from the effective date of this AD, whichever occurs first, as mandatory terminating action to the repetitive inspections of the proposed AD.

The proposed AD would require you to use the service information described previously to perform the inspections.

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

On July 10, 2002, we issued a new version of 14 CFR part 39 (67 FR 47998, 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 2,800 PWC models PW123, PW123B, PW123C, PW123D, PW123E, PW123AF, PW124B, PW125B, PW126A, PW127, PW127E, PW127F, and PW127G turboprop engines of the affected design in the worldwide fleet. We estimate that 473 engines installed on airplanes of U.S. registry would be affected by this proposed AD. We also estimate that it would take about 0.1 work hour per engine to perform the proposed inspection, about 1 work hour per engine to replace the MFC during maintenance, and that the average labor rate is $65 per work hour. Required parts would cost approximately $72,000 per engine. Based on these figures, we estimate the total cost of the proposed AD to U.S. operators to be $34,089,819. The manufacturer has stated that it may provide the new design MFCs at no cost to operators, and that if the MFC is replaced at shop visit, no additional labor costs will be incurred.

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-35-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 & Whitney Canada: Docket No. 2003-NE-35-AD.

Comments Due Date

(a) The FAA must receive comments on this airworthiness directive (AD) action by February 9, 2004.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Pratt & Whitney Canada (PWC) models PW123, PW123B, PW123C, PW123D, PW123E, PW123AF, PW124B, PW125B, PW126A, PW127, PW127E, PW127F, and PW127G turboprop engines, with mechanical fuel controls (MFCs), part numbers (P/Ns) 3244841-21, 3244853-17, 3244855-15, 3244857-14, 3244858-23, 3244871-5, 3244873-4, and 3244874-4, installed. These engines are installed on, but not limited to, Aerospatiale ATR 42 and ATR 72, BAE Systems (Operations) Limited ATP, Bombardier Inc. DHC-8-200 series, DHC-8-300 series, CL-215T, and CL-415, Construcciones Aeronauticas, S.A. (CASA) C-295, Fokker Aircraft B.V. F27 Mark 050, and Mark 060 airplanes.

Unsafe Condition

(d) This AD is prompted by sixteen reports of loss of engine throttle response and overspeed, eight of which resulted in in-flight shutdown. We are issuing this AD to prevent loss of throttle response and overspeed, resulting in engine in-flight shutdown.

Compliance

(e) You are responsible for having the actions required by this AD performed within the compliance times specified unless the actions have already been done.

Initial Gap Inspection

(f) Within 500 hours time-in-service (TIS) after the effective date of the AD, perform a gap inspection between the MFC bypass valve cover and the MFC main body, and disposition the MFC. Follow paragraphs 5.0 through 5.3 of Honeywell Service Information Bulletin (SIB) No. 82, dated September 14, 2001, to do the inspection and MFC disposition.

Repetitive Gap Inspections

(g) At intervals of 1,500 hours TIS from the last gap inspection, perform repetitive gap inspections between the MFC bypass valve cover and the MFC main body and disposition the MFC. Follow paragraphs 5.0 through 5.3 of Honeywell SIB No. 82, dated September 14, 2001, to do the inspection and MFC disposition.

Mandatory Terminating Action

(h) Within 4,500 hours TIS or 24 months from the effective date of this AD, whichever occurs first, replace the MFC with an MFC not having a P/N listed in paragraph (c) of this AD.

(i) Replacement of the MFC with an MFC whose P/N is not listed in paragraph (c) of this AD constitutes mandatory terminating action to the repetitive inspection requirements specified in paragraph (g) of this AD. Information on new design replacement MFCs can be found in PWC Service Bulletin No. PW100-72-21562, Revision 2, dated December 7, 2000.

Alternative Methods of Compliance

(j) The Manager, Engine Certification Office, has the authority to approve alternative methods of compliance for this AD if requested using the procedures found in 14 CFR 39.19.

Material Incorporated by Reference

(k) You must use Honeywell Service Information Bulletin No. 82, dated September 14, 2001, to perform the inspections required by this AD. Approval of incorporation by reference from the Office of the Federal Register is pending.

Related Information

(l) Transport Canada airworthiness directive CF-2002-34, dated July 15, 2002, and Pratt & Whitney Service Bulletin No. PW100-72-21669, dated October 2, 2001, also address the subject of this AD.

Issued in Burlington, Massachusetts, on December 4, 2003.

Jay J. Pardee,

Manager, Engine and Propeller Directorate, Aircraft Certification Service.