E9-30512. Airworthiness Directives; Honeywell International Inc. Auxiliary Power Units Models GTCP36-150(R) and GTCP36-150(RR)

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to adopt a new airworthiness directive (AD) for Honeywell International Inc. auxiliary power units (APU) models GTCP36-150(R) and GTCP36-150(RR). This proposed AD would require inspecting the fuel control unit (FCU) differential pressure (Delta P) sleeve bore for erosion, replacing the FCU if it fails the inspection, and installing a fuel deflector on the Delta P sleeve of the FCU. This proposed AD results from eight reports of fuel leakage from the fuel control unit. We are proposing this AD to prevent fuel leakage in the APU compartment, which could lead to ignition of fuel vapor, creating a fire and explosion hazard resulting in injury, and damage to the APU and the airplane.

DATES:

We must receive any comments on this proposed AD by February 22, 2010.

ADDRESSES:

Use one of the following addresses to comment on this proposed AD.

• Federal eRulemaking Portal: Go to http://www.regulations.gov and follow the instructions for sending your comments electronically.
• Mail: Docket Management Facility, U.S. Department of Transportation, 1200 New Jersey Avenue, SE., West Building Ground Floor, Room W12-140, Washington, DC 20590-0001.
• Hand Delivery: Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.
• Fax: [phone].

FOR FURTHER INFORMATION CONTACT:

Roger Pesuit, Aerospace Engineer, Los Angeles Aircraft Certification Office, FAA, Transport Airplane Directorate, 3960 Paramount Blvd., Lakewood, CA 90712-4137; e-mail: [e-mail]; telephone [phone], fax [phone].

Contact Honeywell International Inc., 111 S. 34th Street, Phoenix, Arizona 85034-2802; Web site: http://portal.honeywell.com/​wps/​portal/​aero;​; telephone No. [phone]; international telephone No. [phone]; for a copy of the service information identified in this proposed AD.

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to send us any written relevant data, views, or arguments regarding this proposal. Send your comments to an address listed under ADDRESSES. Include “Docket No. FAA-2009-0803; Directorate Identifier 2009-NE-34-AD” in the subject line of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. We will consider all comments received by the closing date and may amend the proposed AD in light of those comments.

We will post all comments we receive, without change, to http://www.regulations.gov,, including any personal information you provide. We will also post a report summarizing each substantive verbal contact with FAA personnel concerning this proposed AD. Using the search function of the Web site, anyone can find and read the comments in any of our dockets, including, if provided, the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). You may review the DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78).

Examining the AD Docket

You may examine the AD docket on the Internet at http://www.regulations.gov;​; or in person at the Docket Operations office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this proposed AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Operations office (telephone [phone]) is the same as the Mail address provided in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

Discussion

Over a five-year period, we received eight reports of fuel leakage from the fuel control unit housing on APUs, models GTCP36-150(R) and GTCP36-150(RR). Investigation has found that when the Delta P sleeve is incorrectly positioned inside the fuel control unit housing, a high-velocity stream of fuel can hit the housing. This high-velocity stream can cause cavitation, which is a rapid formation and collapse of vapor pockets in very low-pressure regions of the fuel stream exiting the Delta P sleeve. This condition accelerates erosion of the fuel control housing, eventually causing it to leak. Honeywell International Inc. conducted focused inspections on 228 fuel control unit housings, and found that 97 of them had evidence of erosion. This condition, if not corrected, could result in fuel leakage in the APU compartment, which could lead to ignition of fuel vapor, creating a fire and explosion hazard resulting in injury, and damage to the APU and the airplane.

Relevant Service Information

We have reviewed and approved the technical contents of Honeywell International Inc. Service Bulletin No. 3882840-49-7975, Revision 1, dated April 10, 2009, that describes procedures for inspecting the FCU Delta P sleeve bore for erosion, replacing the FCU if it fails the inspection, and installing a fuel deflector on the Delta P sleeve of the FCU. Installing this fuel deflector will prevent erosion and leakage of the fuel control unit housing.

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 inspecting the FCU Delta P sleeve bore for erosion, replacing the FCU if it fails the inspection, and installing a fuel deflector on the Delta P sleeve of the FCU. The proposed AD would require you to use the service information described previously to perform these actions.

Costs of Compliance

We estimate that this proposed AD would affect four APUs installed on airplanes of U.S. registry. We also estimate that it would take about one work-hour per APU to perform the proposed actions, and that the average labor rate is $80 per work-hour. Required parts would cost about $201 per APU. Based on these figures, we estimate the total cost of the proposed AD to U.S. operators to be $1,124.

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 AD:

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 regulatory evaluation of the estimated costs to comply with this proposed AD. You may get a copy of this summary at the address listed under ADDRESSES.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Incorporation by reference
• Safety

The Proposed Amendment

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:

Honeywell International Inc. (formerly AlliedSignal Inc., formerly Garrett Auxiliary Power Division): Docket No. FAA-2009-0803; Directorate Identifier 2009-NE-34-AD.

Comments Due Date

(a) The Federal Aviation Administration (FAA) must receive comments on this airworthiness directive (AD) action by February 22, 2010.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Honeywell International Inc. Auxiliary Power Units (APU) models GTCP36-150(R) and GTCP36-150(RR). These APUs are installed on, but not limited to, Fokker Services B.V. Model F.28 Mark 0100, and F.28 Mark 0070 airplanes.

Unsafe Condition

(d) This AD results from eight reports of fuel leakage from the fuel control unit. We are issuing this AD to prevent fuel leakage in the APU compartment, which could lead to ignition of fuel vapor, creating a fire and explosion hazard resulting in injury, and damage to the APU and the airplane.

Compliance

(e) You are responsible for having the actions required by this AD performed at the next shop visit of the APU, or the next shop visit of the APU fuel control unit, or before the APU accumulates an additional 4,000 operating hours, whichever occurs first after the effective date of this AD, unless the actions have already been done.

Inspection of the Fuel Control Unit (FCU) Differential Pressure (Delta P) Sleeve Bore

(f) Inspect the FCU Delta P sleeve bore for erosion. Use paragraphs 3.B.(1) through 3.B.(4) of Honeywell International Inc. Service Bulletin (SB) No. 3882840-49-7975, Revision 1, dated April 10, 2009, to do the inspection:

(1) If the erosion in the Delta P sleeve bore is 0.030 inch or more in depth, replace the FCU housing.

(2) If the erosion in the Delta P sleeve bore is less than 0.030 inch in depth, the FCU housing is acceptable for use.

Installation of Fuel Deflector

(g) Install fuel deflector, part number 70720001-1, onto the Delta P sleeve of the FCU. Use paragraphs 3.B(5) through 3.B.(9) of Honeywell International Inc. SB No. 3882840-49-7975, Revision 1, dated April 10, 2009, to do the installation.

Alternative Methods of Compliance

(h) The Manager, Los Angeles 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) Contact Roger Pesuit, Aerospace Engineer, Los Angeles Aircraft Certification Office, FAA, Transport Airplane Directorate, 3960 Paramount Blvd., Lakewood, CA 90712-4137; e-mail: [e-mail]; telephone [phone], fax [phone], for more information about this AD.

(j) Contact Honeywell International Inc., 111 S. 34th Street, Phoenix, Arizona 85034-2802; Web site: http://portal.honeywell.com/​wps/​portal/​aero;​; telephone No. [phone]; international telephone No. [phone]; for a copy of the service information referenced in this AD.

Issued in Burlington, Massachusetts, on December 16, 2009.

Peter A. White,

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