Airworthiness Directives; McDonnell Douglas Model DC-10-10 and DC-10-10F Airplanes, Model DC-10-15 Airplanes, Model DC-10-30 and DC-10-30F (KC-10A and KDC-10) Airplanes, Model DC-10-40 and DC-10-40F Airplanes, Model MD-10-10F and MD-10-30F Airplanes, and Model MD-11 and MD-11F Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Supplemental notice of proposed rulemaking (NPRM); reopening of comment period.

SUMMARY:

We are revising an earlier proposed airworthiness directive (AD) for certain transport category airplanes identified above. The original NPRM would have required modifying the fuel boost pumps. The original NPRM resulted from a fuel boost pump found with blown thermal fuses and a fractured thrust washer. This action revises the original NPRM by referring to new service information, which would require more work. We are proposing this supplemental NPRM to prevent failure of the fuel boost pumps, which could lead to the potential of ignition sources inside fuel tanks. This condition, in combination with flammable fuel vapors, could result in fuel tank explosions and consequent loss of the airplane.

DATES:

We must receive comments on this supplemental NPRM by April 1, 2008.

ADDRESSES:

You may send comments by any of the following methods:

• Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
• Fax: 202-493-2251.
• Mail: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590.
• Hand Delivery: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

For service information identified in this AD, contact Boeing Commercial Airplanes, Long Beach Division, 3855 Lakewood Boulevard, Long Beach, California, 90846, Attention: Data and Service Management, Dept. C1-L5A (D800-0024).

Examining the AD Docket

You may examine the AD docket on the Internet at http://www.regulations.gov ; or in person at the Docket Management Facility 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 Office (telephone 800-647-5527) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT:

Samuel Lee, Aerospace Engineer, Propulsion Branch, ANM-140L, FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California 90712-4137; telephone (562) 627-5262; fax (562) 627-5210.

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to send any written relevant data, views, or arguments about this proposed AD. Send your comments to an address listed under the ADDRESSES section. Include “Docket No. FAA-2007-27339; Directorate Identifier 2006-NM-280-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this proposed AD. We will consider all comments received by the closing date and may amend this proposed AD because 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 we receive about this proposed AD.

Discussion

We issued a notice of proposed rulemaking (NPRM) (the “original NPRM”) to amend 14 CFR part 39 to include an airworthiness directive (AD) that would apply to certain McDonnell Douglas Model DC-10-10 and DC-10-10F airplanes, Model DC-10-15 airplanes, Model DC-10-30 and DC-10-30F (KC-10A and KDC-10) airplanes, Model DC-10-40 and DC-10-40F airplanes, Model MD-10-10F and MD-10-30F airplanes, and Model MD-11 and MD-11F airplanes. That original NPRM was published in the Federal Register on February 26, 2007 (72 FR 8307). That original NPRM proposed to require modifying the fuel boost pumps.

Actions Since Original NPRM Was Issued

Since we issued the original NPRM, Boeing and Crane Hydro-Aire have revised their service information for modifying certain fuel boost pumps. The original NPRM referred to Boeing Alert Service Bulletin DC10-28A254 and Boeing Alert Service Bulletin MD11-28A134, both dated September 8, 2006, which in turn refer to Crane Hydro-Aire Service Bulletin 60-847-28-3, dated May 1, 2006, as an additional source of service information for accomplishing the modification. This supplemental NPRM refers to the revised service information, which would require more work. The additional work involves rerouting the stator-to-connector wire leads for fuel boost pumps modified according to the original issue of Crane Hydro-Aire Service Bulletin 60-847-28-3.

Relevant Service Information

We have reviewed the following service bulletins:

• Boeing Alert Service Bulletin DC10-28A254, Revision 1, dated September 12, 2007, for Model DC-10-10 and DC-10-10F airplanes, Model DC-10-15 airplanes, Model DC-10-30 and DC-10-30F (KC-10A and KDC-10) airplanes, Model DC-10-40 and DC-10-40F airplanes, and Model MD-10-10F and MD-10-30F airplanes.
• Boeing Alert Service Bulletin MD11-28A134, Revision 1, dated September 6, 2007, for Model MD-11 and MD-11F airplanes.

Revision 1 of the service bulletins describe procedures for modifying fuel boost pumps, part numbers (P/Ns) 60-847-1A, -2, and -3, as applicable. The service bulletins also refer to Crane Hydro-Aire Service Bulletin 60-847-28-3, Revision 1, dated July 2, 2007, as an additional source of service information for modifying the fuel boost pumps. The modification involves upgrading the rotor assembly by replacing the Stellite thrust washer with a stainless steel thrust washer manufactured after a certain date, inspecting the stator assembly wire leads, replacing the stator assembly with a new assembly if necessary, rerouting the stator-to-connector wire leads if necessary, and replacing the washers, screws, and other hardware with new parts. Fuel boost pumps modified according to the original issue of Crane Hydro-Aire Service Bulletin 60-847-28-3 need to be reworked by rerouting the stator-to-connector wire leads to prevent damage to the wire leads during pump assembly.

Revision 1 of Crane Hydro-Aire Service Bulletin 60-847-28-3 specifies prior accomplishment of Crane Hydro-Aire Service Bulletin 60-847-1A-28-6, dated February 15, 1973, for fuel boost pump P/N 60-847-1A. Crane Hydro-Aire Service Bulletin 60-847-28-3 also specifies prior accomplishment of Crane Hydro-Aire Service Bulletin 60-847-3-28-13, dated March 17, 1975, for fuel boost pump P/N 60-847-2.

Comments

We gave the public the opportunity to participate in developing this AD. We considered the comments received from the one commenter.

Request To Limit the Scope of the Modification

Boeing requests that we limit the scope of the proposed modification to replacing the Stellite thrust washer with a steel washer. Boeing suggests that we revise paragraph (g) of the supplemental NPRM to specify that operators must modify the fuel boost pump by replacing the Stellite thrust washer with a steel thrust washer. Boeing also suggests that we delete the sentence regarding the modification details from the “Relevant Service Information” section of the original NPRM and replace it with the following sentences: “The primary required modification involves upgrading the rotor assembly to include a new thrust washer. The service information also includes instructions for inspecting the stator assembly wire leads, and rerouting the stator-to-connector wire leads with sleeving, if necessary. Washers, screws, and other miscellaneous hardware are also replaced.” As justification, Boeing states that modification of the fuel boost pumps is solely driven by the need to replace the Stellite thrust washer, and that this action alone will address the unsafe condition. Boeing also states that the other actions mentioned in the “Relevant Service Information” section of the original NPRM are not related to the unsafe condition. Boeing states that those other actions depend on the serviceability of certain components within the pump assembly, which is determined during pump disassembly and the inspection. Boeing asserts that the related information was included in Crane Hydro-Aire Service Bulletin 60-847-28-3 to highlight certain component serviceability checks that are done as part of any pump disassembly and should be emphasized as part of the required action. According to Boeing, this is particularly true for rerouting the stator-to-connector wire leads, since the connector must be removed and replaced with a new connector in order to reroute the wire leads. Boeing states that if the connector is serviceable, the wire leads do not need to be rerouted. Additionally, replacement of the existing attachment hardware, screws, and washers is a consequence of disassembly/assembly of the pump, as part of thrust washer replacement.

We agree that the primary action of the modification is to replace the Stellite thrust washer with a stainless steel thrust washer. We also agree that replacement of the electrical connector of the pump assembly depends upon the inspection results. We have revised the “Relevant Service Information” section of this supplemental NPRM to specify that the modification involves replacing the stator assembly with a new assembly if necessary, and rerouting the stator-to-connector wire leads if necessary.

However, we have determined that both the physical integrity of the thrust washer and the critical configuration control of the routing of the stator lead wires must be addressed in order to minimize potential ignition sources associated with failure of a fuel boost pump. This is accomplished by replacing the Stellite thrust washer, inspecting the stator wire leads, and replacing the stator assembly if necessary. Operators must also verify that the stator-to-connector wire leads are properly routed, and reroute the wire leads if necessary. Therefore, we have not revised paragraph (g) of this supplemental NPRM.

FAA's Determination and Proposed Requirements of the Supplemental NPRM

We are proposing this supplemental NPRM because we evaluated all pertinent information and determined an unsafe condition exists and is likely to exist or develop on other products of the same type design. Certain changes described above expand the scope of the original NPRM. As a result, we have determined that it is necessary to reopen the comment period to provide additional opportunity for the public to comment on this supplemental NPRM.

Costs of Compliance

We estimate that this proposed AD would affect 360 airplanes of U.S. registry. We also estimate that it would take about 3 work-hours per fuel boost pump to comply with this proposed AD. The average labor rate is $80 per work-hour. Required parts would cost about $640 per fuel boost pump. Depending on the airplane configuration, there are between 10 and 19 fuel boost pumps per product. Based on these figures, we estimate the cost of this proposed AD to the U.S. operators to be between $3,168,000 and $6,019,200, or between $8,800 and $16,720 per product.

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 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 this 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. Will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act.

You can find our regulatory evaluation and the estimated costs of compliance in the AD Docket.

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 FAA 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.