Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report summarizing each FAApublic contact concerned with the substance of this proposal will be filed in the Rules Docket. [[Page 82958]]

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this action must submit a selfaddressed, stamped postcard on which the following statement is made: ``Comments to Docket Number 2000NM308AD.'' The postcard will be date stamped and returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request to the FAA, Transport Airplane Directorate, ANM114, Attention: Rules Docket No. 2000NM308AD, 1601 Lind Avenue, SW., Renton, Washington 980554056.

Discussion

The FAA has received a report indicating that the functional test performed during production of certain Boeing Model 737300, 737400, 737500, 737600, 737700, 737800, 757200, 757200PF, 757200CB, and 757300 series airplanes is not adequate to ensure that two electrical circuits that close the fuel shutoff valve on the wing spar can both supply electrical power to the fuel shutoff valve. Investigation revealed three airplanes in service that had wiring problems. The functional test only verifies that the fuel shutoff valve operates correctly, and only one of the two circuits needs to supply power for the fuel shutoff valve to operate correctly. The design incorporates two separate electrical circuits that close the fuel shutoff valve to ensure that, if one circuit is severed by debris from an uncontained engine failure, one circuit will still be available so that fuel can be shut off from the failed engine. However, if only one of the two electrical circuits that close the fuel shutoff valve is supplying power, and it is severed as a result of an uncontained engine failure, the flight crew will be unable to shut off the flow of fuel to the failed engine. This condition, if not corrected, could result in a fire spreading to other parts of the airplane.

Explanation of Relevant Service Information

The FAA has reviewed and approved Boeing Special Attention Service Bulletin 737281164, dated August 24, 2000, which applies to certain Boeing Model 737300, 737400, and 737500 series airplanes. That service bulletin describes a onetime test of the two electrical circuits that close the fuel shutoff valve on each wing spar to determine if there is continuity. The service bulletin also notes what procedures to use to locate and repair any discontinuity.

The FAA has also reviewed and approved the following service bulletins, all dated October 26, 2000:

These service bulletins describe procedures for a onetime test to measure the voltage of the two electrical circuits that close the fuel shutoff valve on the wing spar, and specify appropriate procedures to be used if inappropriate voltage is found.

Accomplishment of the actions specified in the applicable service bulletin is intended to adequately address the identified unsafe condition.

Explanation of Requirements of Proposed Rule

Since an unsafe condition has been identified that is likely to exist or develop on other products of this same type design, the proposed AD would require accomplishment of the actions specified in the applicable service bulletin described previously.

Cost Impact

There are approximately 3,403 airplanes of the affected design in the worldwide fleet.

The FAA estimates that this proposed AD would affect 795 Model 737 300, 400, and 500 airplanes of U.S. registry. The proposed test would take approximately 1 work hour on each of these airplanes, at an average labor rate of $60 per work hour. Based on these figures, the FAA estimates the cost impact of the proposed AD on U.S. operators of these airplanes to be $47,700, or $60 per airplane.

The FAA estimates that this proposed AD would affect 820 Model 737 600, 737700, 737800, 757200, 757200PF, 757200CB, and 757300 airplanes of U.S. registry. The proposed test would take approximately 3 work hours on each of these airplanes, at an average labor rate of $60 per work hour. Based on these figures, the FAA estimates the cost impact of the proposed AD on U.S. operators of these airplanes to be $147,600, or $180 per airplane.

The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the proposed requirements of this AD action, and that no operator would accomplish those actions in the future if this proposed AD were not adopted. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions.

Regulatory Impact

The regulations proposed herein 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. Therefore, it is determined that this proposal would not have federalism implications under Executive Order 13132.

For the reasons discussed above, I certify that 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) if promulgated, 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. A copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES. List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Safety. The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend part 39 of the Federal Aviation Regulations (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. Section 39.13 is amended by adding the following new airworthiness directive:
Boeing: Docket 2000NM308AD.

[[Page 82959]]

Applicability: The following models and series of airplanes as listed in the service bulletins below, certificated in any category: Airplane model Boeing special attention service bulletin 737300, 737400, 737500.... 737281164, dated August 24, 2000. 737600, 737700, 737800.... 737281160, Revision 1, dated October 26, 2000.
757200, 757200PF, 757200CB 757280060, Revision 1, dated October 26, 2000.
757300...................... 757280061, Revision 1, dated October 26, 2000.

Note 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the
requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (b) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously.

To prevent inability to shut off the flow of fuel to an engine after an uncontained engine failure, which could result in a fire spreading to other parts of the airplane, accomplish the following: Test and Repair
(a) Within 6 months after the effective date of this AD, perform a test to determine if there is continuity or to measure voltage, as applicable, of the two electrical circuits that close the fuel shutoff valve on the wing spar. Do the test per Boeing Special Attention Service Bulletin 737281164, dated August 24, 2000 (for Boeing Model 737300, 737400, and 737500 series airplanes); or Boeing Special Attention Service Bulletin 737281160, Revision 1 (for Boeing Model 737600, 737700, and 737800 series airplanes); Boeing Special Attention Service Bulletin 757280060, Revision 1 (for Boeing Model 757200, 757200PF, and 757200CB series
airplanes); or Boeing Special Attention Service Bulletin 75728 0061, Revision 1 (for Boeing Model 757300 series airplanes); all dated October 26, 2000; as applicable.
(1) For Boeing Model 737300, 737400, and 737500 series airplanes: If any discontinuity is detected, prior to further flight, repair per Boeing Special Attention Service Bulletin 73728 1164.
(2) For airplane models other than those listed in paragraph (a)(1) of this AD: If any measurement is not between 21 and 34 volts DC, prior to further flight, repair per the applicable service bulletin.

Note 2: Tests accomplished per Boeing Special Attention Service Bulletin 737281160 (for Boeing Model 737600, 737700, and 737800 series airplanes), dated June 5, 2000; Boeing Special Attention Service Bulletin 757280060 (for Boeing Model 757200, 757200PF, and 757200CB series airplanes), dated June 15, 2000; or Boeing Special Attention Service Bulletin 757280061, dated June 15, 2000 (for Boeing Model 757300 series airplanes); as applicable; are acceptable for compliance with paragraph (a) of this AD.
Alternative Methods of Compliance
(b) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Seattle ACO.

Note 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO.
Special Flight Permits
(c) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished.

Issued in Renton, Washington, on December 22, 2000. John J. Hickey,
Manager, Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. 0033344 Filed 122800; 8:45 am] BILLING CODE 491013P

FOR FURTHER INFORMATION CONTACT Kathrine Rask, Aerospace Engineer, Propulsion Branch, ANM140S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 980554056; telephone (425) 2271547; fax (425) 2271181.