E6-2454. Airworthiness Directives; Rolls-Royce Corporation (Formerly Allison Engine Company) 501-D Series Turboprop Engines

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to supersede an existing airworthiness directive (AD) for Rolls-Royce Corporation (formerly Allison Engine Company) (RRC) 501-D series turboprop engines. That AD currently requires removal from service of certain turbine rotor components at reduced life limits. This proposed AD would require the same actions but adds two new life limits. This proposed AD results from RRC reevaluating and revising component life limits for 501-D22 series turboprop engines. We are proposing this AD to prevent uncontained turbine rotor failure resulting in an in-flight engine shutdown and possible damage to the airplane.

DATES:

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

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. 2001-NE-01-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 Rolls-Royce Corporation, P.O. Box 420, Indianapolis, IN 46206-0420; telephone [phone]; fax [phone].

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:

Michael Downs, Aerospace Engineer, Chicago Aircraft Certification Office, FAA, 2300 East Devon Avenue, Des Plaines, IL 60018; 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. 2001-NE-01-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.

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

On March 25, 2003, we issued AD 2003-07-02, Amendment 39-13098 (68 FR 15937, April 2, 2003). That AD requires removing from service certain turbine rotor components at reduced life limits. That AD resulted from RRC updating material properties and recalculating component life limits. That condition, if not corrected, could result in uncontained turbine rotor failure resulting in an in-flight engine shutdown and possible damage to the airplane.

Actions Since AD 2003-07-02 Was Issued

Since we issued AD 2003-07-02, RRC reevaluated turbine wheel assembly and turbine wheel spacer assembly life limits for 501-D series turboprop engines. RRC changed certain life limits for the 501-D22 series turboprop engines because of recent improvements in how low-cycle-fatigue life is determined. RRC similarly reduced the life limit of 2nd-3rd-stage spacer assemblies, part numbers (P/Ns) 23033464 and 6842683, installed on 501-D22 series turboprop engines.

FAA's Determination and Requirements of the Proposed AD

We have evaluated all pertinent information and identified an unsafe condition that is likely to exist or develop on other products of this same type design. We are proposing this AD, which would require the same actions specified in AD 2003-07-02, but for 501-D22 series turboprop engines, it would add a life limit of 5,200 cycles-in-service for 2nd-3rd-stage spacer assemblies, P/Ns 23033464 and 6842683.

Costs of Compliance

We estimate that this proposed AD would affect 684 engines installed on aircraft of U.S. registry. The proposed action does not impose any additional labor costs if performed at the time of scheduled engine overhaul. Required parts would cost about $45,000 per engine. Based on these figures, we estimate the total cost of the proposed AD to U.S. operators to be $30,780,000.

Special Flight Permits Paragraph Removed

Paragraph (f) of the current AD, AD 2003-07-02, contains a paragraph pertaining to special flight permits. Even though this proposed AD does not contain a similar paragraph, we have made no changes with regard to the use of special flight permits to operate the airplane to a repair facility to do the work required by this proposed AD. In July 2002, we published a new Part 39 that contains a general authority regarding special flight permits and airworthiness directives; see Docket No. FAA-2004-8460, Amendment 39-9474 (69 FR 47998, July 22, 2002). Thus, when we now supersede ADs we will not include a specific paragraph on special flight permits unless we want to limit the use of that general authority granted in section 39.23.

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. 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. 2001-NE-01-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 removing Amendment 39-13098 (68 FR 15937, April 2, 2003) and by adding a new airworthiness directive to read as follows:

Rolls-Royce Corporation: Docket No. 2001-NE-01-AD.

Comments Due Date

(a) The Federal Aviation Administration (FAA) must receive comments on this airworthiness directive (AD) action by April 24, 2006.

Affected ADs

(b) This AD supersedes AD 2003-07-02, Amendment 39-13098.

Applicability

(c) This AD applies to Rolls-Royce Corporation (formerly Allison Engine Company) (RRC) 501-D series turboprop engines. These engines are installed on, but not limited to, Lockheed 188 series and 382 series turboprop airplanes, Airbus 377SG5-F (Super Guppy) airplanes, and Convair Models 340 and 440 airplanes which have RRC 501-D series turboprop engines installed under Supplemental Type Certificate No. SE1161EA. These latter models are commonly referred to as Convair 580/580A or 5800 models.

(d) This AD results from RRC reevaluating and revising component life limits for 501-D22 series turboprop engines. We are issuing this AD to prevent uncontained turbine rotor failure resulting in an in-flight engine shutdown and possible damage to the airplane.

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.

501-D13 Series Engines

(f) For 501-D13 series engines, remove turbine wheels and spacers from service as specified in the following Table 1:

Table 1.—501-D13 Series Life Limits

Part name	Part number	Life limit for wheels that have complied with commercial overhaul information letter (COIL) 401, dated May 1978	Life limit for wheels that have not complied with COIL 401, dated May 1978
(1) Second-stage turbine wheel assembly	6847142 and 6876892	Remove from service before or upon accumulating 16,000 cycles-in-service (CIS)	Remove from service before or upon accumulating 12,000 CIS.
(2) Third-stage turbine wheel assembly	6845883 and 6849743	Remove from service before or upon accumulating 13,000 CIS	Remove from service before or upon accumulating 10,000 CIS.
(3) Fourth-stage turbine wheel assembly	6876468	Remove from service before or upon accumulating 24,000 CIS	Remove from service before or upon accumulating 18,000 CIS.

501-D22 Series Engines

(g) For 501-D22 series engines, remove turbine wheels and spacers from service as specified in the following Table 2:

Table 2.—501-D22 Series Life Limits

Part name	Part number	Remove from service
(1) Third-stage turbine wheel assembly	6855083	Before or upon accumulating 10,000 cycles-in-service (CIS).
(2) 1st-2nd-stage spacer assembly	6844632, 23033463, 23064854, and 23064858	Before or upon accumulating 4,700 CIS.
(3) 1st-2nd-stage spacer assembly	23056966	(i) Before or upon accumulating 8,000 CIS. (ii) If the 1st-2nd-stage spacer assembly passes the hardness criteria in RRC Commercial Engine Bulletin CEB-A-72-1135, then before or upon accumulating 10,000 CIS.
(4) 2nd-3rd-stage spacer assembly	23033456	Before or upon accumulating 4,200 CIS.
(5) 2nd-3rd-stage spacer assembly	23033464 and 6842683	Before or upon accumulating 5,200 CIS.
(6) 3rd-4th-stage spacer assembly	6844794 prior to revision letter “R”	Before or upon accumulating 5,100 CIS.

Alternative Methods of Compliance

(h) The Manager, Chicago Aircraft 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.

Related Information

(i) Information on 501-D13 series engine turbine life limits can be found in RRC Commercial Service Letter (CSL) No. CSL-120, Revision No. 52, dated July 22, 2002.

(j) Information on 501-D22 series engine turbine life limits can be found in RRC CSL No. CSL-1001, Revision No. 20, dated April 5, 2005.

Issued in Burlington, Massachusetts, on February 14, 2006.

Ann C. Mollica,

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