This proposed AD would also allow accomplishing the revision to the AWLs section of the Instructions for Continued Airworthiness in accordance with later revisions of the MPD as an acceptable method of compliance if they are approved by the Manager, Seattle Aircraft Certification Office, FAA.

Costs of Compliance

We estimate that this proposed AD would affect 754 aircraft of U.S. registry. The following table provides the estimated costs, at an average labor rate of $80 per hour, for U.S. operators to comply with this proposed AD.
Estimated Costs Cost per Action Work hours Parts product Fleet cost Installation of GFI relays............. 8 $11,010................... $11,650 $8,784,100 Maintenance program revision........... 1 None...................... $80 $60,320 [[Page 12912]]

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 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: Boeing: Docket No. FAA20080269; Directorate Identifier 2007NM 320AD.
Comments Due Date
(a) We must receive comments by April 25, 2008.
Affected ADs
(b) None.
Applicability
(c) This AD applies to Boeing Model 737600, 700, 700C, 800, and 900 series airplanes, certificated in any category; as identified in Boeing Alert Service Bulletin 73728A1201, dated February 19, 2007.

Note 1: This AD requires revisions to certain operator maintenance documents to include new inspections. Compliance with these inspections is required by 14 CFR 91.403(c). For airplanes that have been previously modified, altered, or repaired in the areas addressed by these inspections, the operator may not be able to accomplish the inspections described in the revisions. In this situation, to comply with 14 CFR 91.403(c), the operator must request approval for an alternative method of compliance (AMOC) according to paragraph (i) of this AD. The request should include a description of changes to the required inspections that will ensure the continued operational safety of the airplane.
Unsafe Condition
(d) This AD results from fuel system reviews conducted by the manufacturer. We are issuing this AD to prevent pump housing burn through due to electrical arcing, which could create a potential ignition source inside a fuel tank. This condition, in combination with flammable fuel vapors, could result in a fuel tank explosion and consequent loss of the airplane.
Compliance
(e) Comply with this AD within the compliance times specified, unless already done.
Replacement
(f) Within 60 months after the effective date of this AD, replace the power control relays in the P91 and P92 power
distribution panels for the fuel boost and override pumps with new improved relays having a ground fault interrupter (GFI) feature, in accordance with the Accomplishment Instructions of the service bulletin.

Note 2: The Boeing service bulletin refers to Honeywell Service Bulletin 11519322461 and Honeywell Service Bulletin 11519342462, both dated November 10, 2006, as additional sources of service information for replacement of the power control relays in the P91 and P92 power distribution panels.
Airworthiness Limitations (AWLs) Revision
(g) Concurrently with accomplishing the actions specified in paragraph (f) of this AD, revise the AWLs section of the
Instructions for Continued Airworthiness by incorporating AWL No. 28AWL20 of Subsection F of the Boeing 737600/700/800/900
Maintenance Planning Data (MPD) Document, D626A001CMR, Section 9, Revision March 2007 R2 (hereafter referred to as ``the MPD''). No Alternative Inspections or Inspection Intervals
(h) After accomplishing the action specified in paragraph (g) of this AD, no alternative inspections or inspection intervals may be used unless the inspections or intervals are part of a later revision of the MPD that is approved by the Manager, Seattle ACO; or unless the inspections or intervals are approved as an AMOC in accordance with the procedures specified in paragraph (j) of this AD.
Alternative Methods of Compliance (AMOCs)
(i)(1) The Manager, Seattle ACO, FAA, ATTN: Jen Pei, Aerospace Engineer, Systems and Equipment Branch, ANM130S, 1601 Lind Avenue, SW., Renton, Washington 980573356; telephone (425) 9176409; fax (425) 9176590; 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. E84773 Filed 31008; 8:45 am]
BILLING CODE 491013P

FOR FURTHER INFORMATION CONTACT Jen Pei, Aerospace Engineer, Systems and Equipment Branch, ANM130S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue SW., Renton, Washington 980573356; telephone (425) 9176409; fax (425) 9176590.