Airworthiness Directives; Rolls-Royce Corporation (Formerly Allison Engine Company, Allison Gas Turbine Division, and Detroit Diesel Allison) (RRC) 250-B and 250-C Series Turboshaft and 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 certain RRC 250-B and 250-C series turboshaft and turboprop engines. This proposed AD would require a one-time inspection of the fuel nozzle screen for contamination, and if contamination is found, inspection and cleaning of the entire aircraft fuel system before further flight. This proposed AD would also require replacement of the fuel nozzle with a new design fuel nozzle, at the next fuel nozzle overhaul or by June 30, 2006, whichever occurs first. This proposed AD results from 10 reports of engine power loss with accompanying collapse of the fuel nozzle screen, due to fuel contamination. We are proposing this AD to prevent sudden loss of engine power and uncommanded shutdown of the engine due to fuel contamination and collapse of the screen in the fuel nozzle.

DATES:

We must receive any comments on this proposed AD by July 6, 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. 2004-NE-10-AD, 12 New England Executive Park, Burlington, MA 01803-5299.
• By fax: (781) 238-7055.
• By e-mail: 9-ane-adcomment@faa.gov.

You can get the service information identified in this proposed AD from Rolls-Royce Corporation, P.O. Box 420, Indianapolis, IN 46206-0420; telephone (317) 230-6400; fax (317) 230-4243.

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:

John Tallarovic, Aerospace Engineer, Chicago Aircraft Certification Office, FAA, 2300 East Devon Avenue, Des Plaines, IL 60018-4696; telephone (847) 294-8180; fax (847) 294-7834.

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. 2004-NE-10-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 can 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

The FAA has received 10 reports of 250-B and 250-C series turboshaft and turboprop engines experiencing loss of engine power due to fuel contamination and collapse of the fuel nozzle screen. The existing screen of the fuel nozzle, part number (P/N) 6890917, 6899001, or 6852020, may collapse when clogging occurs. Following a 1997 accident resulting from a complete engine power loss due to fuel contamination, the National Transportation Safety Board issued Safety Recommendations A-98-84 and A-98-85. In response, we issued Special Airworthiness Information Bulletin (SAIB) No. CE-01-10 to remind operators of the importance of maintaining a clean aircraft fuel system. We also issued an NPRM, Docket No. 99-NE-47-AD, on April 25, 2000 that would require a one-time inspection of the fuel nozzle screen for model 250-C18 and -C20 engines. That NPRM was withdrawn because it appeared that the problem would be solved by the increased awareness of the importance of a clean fuel system following the issuance of SAIB CE-01-10. Shortly after the NPRM was withdrawn another accident resulted from a complete engine power loss due to fuel contamination. After that initial NPRM was issued, the manufacturer conducted extensive research into fuel contamination and introduced a new design fuel nozzle. This fuel nozzle design incorporates a new screen design that is resistant to collapse when contaminated. This NPRM is being issued because collapsed fuel nozzle screens, and the resulting engine power loss, due to fuel contamination, remains a problem. The scope of this NPRM is expanded from the original NPRM to include all Rolls-Royce Corporation model 250 engines because the improvement is equally applicable to all of these engines. This condition, if not corrected, could result in sudden loss of engine power and uncommanded shutdown of the engine.

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. Therefore, we are proposing this AD, which would require:

• A one-time inspection of the fuel nozzle screen for contamination, within 150 operating hours after the effective date of the proposed AD; and
• Inspection and cleaning of the entire aircraft fuel system before further flight, if contamination is found; and
• Replacement of the fuel nozzle with a serviceable (new design) fuel nozzle, at the next fuel nozzle overhaul or by June 30, 2006, whichever occurs first.

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 about 15,000 RRC 250-B and 250-C series turboshaft and turboprop engines of the affected design in the worldwide fleet. We estimate that 10,000 engines installed on aircraft of U.S. registry would be affected by this proposed AD. We also estimate that it would take about one work hour per engine to perform the proposed actions, and that the average labor rate is $65 per work hour. In addition, operators can either replace the fuel nozzle with a new one at a cost of about $2,595 or have the existing nozzle overhauled at a cost of about $850. We estimate that about 80% of the fuel nozzles will be overhauled and 20% will be replaced with a new nozzle. Therefore, we estimate that the required parts would cost, on average, about $1,200 per engine. Based on these figures, we estimate the total cost of the proposed AD to U.S. operators to be $12,650,000.

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. 2004-NE-10-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.