Revision 1 of the service bulletins describe procedures for modifying fuel boost pumps, part numbers (P/Ns) 608471A, 2, and 3, as applicable. The service bulletins also refer to Crane HydroAire Service Bulletin 60847283, 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 statortoconnector 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 HydroAire Service Bulletin 60847283 need to be reworked by rerouting
[[Page 12302]]
the statortoconnector wire leads to prevent damage to the wire leads during pump assembly.

Revision 1 of Crane HydroAire Service Bulletin 60847283 specifies prior accomplishment of Crane HydroAire Service Bulletin 60 8471A286, dated February 15, 1973, for fuel boost pump P/N 60847 1A. Crane HydroAire Service Bulletin 60847283 also specifies prior accomplishment of Crane HydroAire Service Bulletin 6084732813, dated March 17, 1975, for fuel boost pump P/N 608472.

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 statortoconnector 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 HydroAire Service Bulletin 60847283 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 statortoconnector 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 statortoconnector 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 statortoconnector 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 workhours per fuel boost pump to comply with this proposed AD. The average labor rate is $80 per workhour. 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: [[Page 12303]]

PART 39AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701.

Sec. 39.13 [Amended]

2. The FAA amends Sec. 39.13 by adding the following new AD: McDonnell Douglas: Docket No. FAA200727339; Directorate Identifier 2006NM280AD.
Comments Due Date
(a) We must receive comments by April 1, 2008.
Affected ADs
(b) None.
Applicability
(c) This AD applies to the airplanes identified in paragraphs (c)(1) and (c)(2) of this AD, certificated in any category. (1) McDonnell Douglas Model DC1010 and DC1010F airplanes, Model DC1015 airplanes, Model DC1030 and DC1030F (KC10A and KDC10) airplanes, Model DC1040 and DC1040F airplanes, and Model MD1010F and MD1030F airplanes; as identified in Boeing Alert Service Bulletin DC1028A254, Revision 1, dated September 12, 2007. (2) McDonnell Douglas Model MD11 and MD11F airplanes, as identified in Boeing Alert Service Bulletin MD1128A134, Revision 1, dated September 6, 2007.
Unsafe Condition
(d) This AD results from a fuel boost pump found with blown thermal fuses and a fractured thrust washer. We are issuing this AD 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.
Compliance
(e) Comply with this AD within the compliance times specified, unless already done.
Service Bulletin Reference
(f) The term ``service bulletin,'' as used in this AD, means the following service bulletins, as applicable:
(1) For the airplanes identified in paragraph (c)(1) of this AD, Boeing Alert Service Bulletin DC1028A254, Revision 1, dated September 12, 2007.
(2) For the airplanes identified in paragraph (c)(2) of this AD, Boeing Alert Service Bulletin MD1128A134, Revision 1, dated September 6, 2007.

Note 1: Boeing Alert Service Bulletin DC1028A254, Revision 1, dated September 12, 2007; and Boeing Alert Service Bulletin MD11 28A134, Revision 1, dated September 6, 2007; refer to Crane Hydro Aire Service Bulletin 60847283, Revision 1, dated July 2, 2007, as an additional source of service information for accomplishing the modification in paragraph (g) of this AD.
Modification
(g) At the applicable compliance time specified in paragraph (g)(1) or (g)(2) of this AD, modify the fuel boost pumps having part numbers 608471A, 2, and 3, in accordance with the Accomplishment Instructions of the applicable service bulletin.
(1) For fuel boost pumps identified as Configuration 1 or 2 in Table 1 of paragraph 1.E. of the applicable service bulletin, do the modification within 120 months after the effective date of this AD. (2) For fuel boost pumps identified as Configuration 3 in Table 1 of paragraph 1.E. of the applicable service bulletin, do the modification within 72 months after the effective date of this AD. Alternative Methods of Compliance (AMOCs)
(h)(1) The Manager, Los Angeles Aircraft Certification Office, FAA, ATTN: Samuel Lee, Aerospace Engineer, Propulsion Branch, ANM 140L, 3960 Paramount Boulevard, Lakewood, California 907124137; telephone (562) 6275262; fax (562) 6275210; has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19.
(2) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Before using any approved AMOC on any airplane to which the AMOC applies, notify your appropriate principal inspector (PI) in the FAA Flight Standards District Office (FSDO), or lacking a PI, your local FSDO.

Issued in Renton, Washington, on March 3, 2008.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. E84475 Filed 3608; 8:45 am]
BILLING CODE 491013P

FOR FURTHER INFORMATION CONTACT Samuel Lee, Aerospace Engineer, Propulsion Branch, ANM140L, FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California 907124137; telephone (562) 6275262; fax (562) 6275210.