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Proposed Rule

Airworthiness Directives; Pratt & Whitney Canada Models PW118, PW120, PW120A, and PW121 Turboprop Engines

Document Details

Information about this document as published in the Federal Register.

Published Document

This document has been published in the Federal Register. Use the PDF linked in the document sidebar for the official electronic format.

Start Preamble

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 PW118, PW120, PW120A, and PW121 turboprop engines. This proposed AD would require replacing the low pressure rotor speed (NL) sensor port sealing tube and reworking or replacing the external air tube connecting the P2.5/P3 switching valve to the rear inlet case. This proposed AD is prompted by a report of an internal oil fire in the engine intercompressor case (ICC). A fire in the ICC could cause the existing tubes to disengage due to melted brazing on the tubes. Once these tubes disengage, the ICC fire then develops into an external fire within the engine nacelle cavity. The actions specified in this proposed AD are intended to prevent fire in the engine nacelle cavity, in-flight engine shutdown, and airplane damage.

DATES:

We must receive any comments on this proposed AD by August 5, 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-11-AD, 12 New England Executive Park, Burlington, MA 01803-5299.
  • By fax: (781) 238-7055.
  • By e-mail: 9-ane-adcomment@faa.gov

You may get the service information identified in this proposed AD from Pratt & Whitney Canada, Technical Publications Department, 1000 Marie Victorin, Longueuil, Quebec J4G 1A1.

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

Start Further Info

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 (781) 238-7178; fax (781) 238-7199.

End Further Info End Preamble Start Supplemental Information

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-11-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 models PW118, PW120, PW120A, and PW121 turboprop engines. Transport Canada advises that they have received a report of an internal oil fire in the engine ICC. An ICC fire melts the brazing on the external air tube connected to the P2.5/P3 switching valve, and on the low pressure rotor speed (NL) sensor port sealing tube, allowing both to disengage. Once these tubes disengage, the ICC fire then develops into an external fire within the engine nacelle cavity, resulting in in-flight engine shutdown and potential airplane damage.

Relevant Service Information

We have reviewed and approved the technical contents of PWC Service Bulletin (SB) No. 20914, Revision 4, dated December 14, 2001. That SB describes procedures for replacing the low pressure rotor speed (NL) sensor port sealing tube and reworking or replacing the external air tube connecting the P2.5/P3 switching valve to the rear inlet case. Transport Canada classified this SB as mandatory and issued airworthiness directive No. CF-2002-10, dated January 28, 2002, in order to ensure the airworthiness of these PWC models PW118, PW120, PW120A, and PW121 turboprop engines in Canada.

FAA's Determination and Requirements of the Proposed AD

These PWC models PW118, PW120, PW120A, and PW121 turboprop Start Printed Page 33886engines, manufactured in Canada, are type-certificated for operation in the United States under the provisions of § 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 the low pressure rotor speed (NL) sensor port sealing tube and reworking or replacing the external air tube connecting the P2.5/P3 switching valve to the rear inlet case. The proposed AD would require that these actions be done using the service information described previously.

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 1,933 PWC models PW118, PW120, PW120A, and PW121 turboprop engines of the affected design in the worldwide fleet. We estimate that 1,160 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 installed engine to replace the parts, and that the average labor rate is $60 per work hour. Required parts would cost approximately $1,966 per engine. Based on these figures, the total replacement cost of the proposed AD to U.S. operators is estimated to be $2,419,760. We also estimate that it would take approximately 2 work hours per tube to perform the rework in lieu of tube replacement, and required parts for rework would cost approximately $197 per engine. Based on these figures, the total rework cost of the proposed AD to U.S. operators is estimated to be $367,720. PWC has informed the FAA that it may provide the parts and labor to the operators at no cost, thereby substantially reducing the cost of the 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-11-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.

End Authority
[Amended]

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

Pratt & Whitney Canada: Docket No. 2003-NE-11-AD.

Comments Due Date

(a) The FAA must receive comments on this airworthiness directive (AD) action by August 5, 2003.

Affected ADs

(b) None.

Applicability

(c) This AD is applicable to Pratt & Whitney Canada (PWC) models PW118, PW120, PW120A, and PW121 turboprop engines. These engines are installed on, but not limited to, Empresa Brasileira de Aeronautica (EMBRAER) EMB-120RT, 120ER, and 120FC, Bombardier Inc. (formerly Dehavilland of Canada) DHC-8-100 series, and Aerospatiale ATR 42-200, -300, and -320 airplanes.

Unsafe Condition

(d) This AD was prompted by a report of an internal oil fire in the engine intercompressor case (ICC). A fire in the ICC could cause the low pressure rotor speed (NL) sensor port sealing tube and the external air tube connecting the P2.5/P3 switching valve to the rear inlet case, to disengage due to melted brazing on the tubes. Once these tubes disengage, the ICC fire then develops into an external fire within the engine nacelle cavity. The actions specified in this AD are intended to prevent fire in the engine nacelle cavities, in-flight engine shutdown, and airplane damage.

Compliance

(e) Compliance with this AD is required at the next engine shop visit, or within 90 days after the effective date of this AD, whichever occurs first, unless already done.

Low Pressure Rotor Speed (NL) Sensor Port Sealing Tube

(f) Replace the low pressure rotor speed (NL) sensor port sealing tube with an improved durability tube, in accordance with paragraphs 2.A. and 2.B., Accomplishment Instructions of PWC Service Bulletin (SB) No. 20914, Revision 4, dated December 14, 2001.

Switching Valve-to-Rear Inlet Case Sealing Air Tube Assembly

(g) Remove the switching valve-to-rear inlet case sealing air tube assembly, in accordance with paragraph 2.C., Accomplishment Instructions of PWC SB No. 20914, Revision 4, dated December 14, 2001, and do the following:

(1) Either install an improved durability switching valve-to-rear inlet case sealing air tube assembly, in accordance with paragraph 2.G., Accomplishment Instructions of PWC SB No. 20914, Revision 4, dated December 14, 2001; or

(2) Rework the switching valve-to-rear inlet case sealing air tube assembly and install tube assembly, in accordance with paragraphs 2.D., 2.F., and 2.G., Accomplishment Instructions of PWC SB No. 20914, Revision 4, dated December 14, 2001.

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) The replacements and rework must be done in accordance with PWC SB No. 20914, Revision 4, dated December 14, 2001.

Related Information

(j) The subject of this AD is addressed in Transport Canada airworthiness directive No. CF-2002-10, dated January 28, 2002.

Start Signature
Start Printed Page 33887

Issued in Burlington, Massachusetts, on May 30, 2003.

Jay J. Pardee,

Manager, Engine and Propeller Directorate, Aircraft Certification Service.

End Signature End Part End Supplemental Information

[FR Doc. 03-14276 Filed 6-5-03; 8:45 am]

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