04-20596. Airworthiness Directives; Boeing Model 747-200F and -400 Series Airplanes; Model 767-400ER Series Airplanes; and Model 777 Series Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to adopt a new airworthiness directive (AD) for certain Boeing Model 747-200F and -400 series airplanes; Model 767-400ER series airplanes; and Model 777 series airplanes. This proposed AD would require replacing the frequency converter(s) used to supply electrical power for utility outlets (for the galley, medical equipment, or personal computers) with modified frequency converter(s). This proposed AD also would require any specified action and related concurrent actions, as necessary. This proposed AD is prompted by a report that a hard short condition between the frequency converter's output and its downstream circuit breakers will produce a continuous circuit that could cause the undersized output wiring to overheat. We are proposing this AD to prevent the overheating of the frequency converter's undersized output wiring, which could lead to the failure of a wire bundle, and consequent adverse effects on other systems sharing the affected wire bundle.

DATES:

We must receive comments on this proposed AD by October 28, 2004.

ADDRESSES:

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

• DOT Docket Web site: Go to http://dms.dot.gov and follow the instructions for sending your comments electronically.
• Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your comments electronically.
• Mail: Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street SW, Nassif Building, room PL-401, Washington, DC 20590.
• By fax: [phone].
• Hand Delivery: Room PL-401 on the plaza level of the Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

For service information identified in this proposed AD, contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207.

You can examine the contents of this AD docket on the Internet at http://dms.dot.gov,, or at the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street SW, room PL-401, on the plaza level of the Nassif Building, Washington, DC.

FOR FURTHER INFORMATION CONTACT:

Binh Tran, Aerospace Engineer, Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Docket Management System (DMS)

The FAA has implemented new procedures for maintaining AD dockets electronically. As of May 17, 2004, new AD actions are posted on DMS and assigned a docket number. We track each action and assign a corresponding directorate identifier. The DMS AD docket number is in the form “Docket No. FAA-2004-99999.” The Transport Airplane Directorate identifier is in the form “Directorate Identifier 2004-NM-999-AD.” Each DMS AD docket also lists the directorate identifier (“Old Docket Number”) as a cross-reference for searching purposes.

Comments Invited

We invite you to submit any written relevant data, views, or arguments regarding this proposed AD. Send your comments to an address listed under ADDRESSES. Include “Docket No. FAA-2004-19082; Directorate Identifier 2004-NM-79-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 submitted 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://dms.dot.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 that website, anyone can find and read the comments in any of our dockets, including 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 DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78), or you may visit http://dms.dot.gov.

We are reviewing the writing style we currently use in regulatory documents. We are interested in your comments on whether the style of this document is clear, and your suggestions to improve the clarity of our communications that affect you. You can get more information about plain language at http://www.faa.gov/​language and http://www.plainlanguage.gov.

Examining the Docket

You can examine the AD docket, which contains the proposed AD, comments, and any final disposition, in person at the Docket Management Facility office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Management Facility office (telephone [phone]) is located on the plaza level of the Nassif Building at the DOT street address stated in the ADDRESSES section. Comments will be available in the AD docket shortly after the DMS receives them.

Discussion

Boeing analysis has shown that on certain Boeing Model 747-200F and -400 series airplanes, Model 767-400ER series airplanes, and Model 777 series airplanes, a hard short condition between the output of the frequency converter (usually located in the main equipment center) and its downstream circuit breaker will produce a continuous current of 55 amps. The continuous current causes the output wiring to exceed its wire temperature rating of 150 degrees Celsius. This condition, if not corrected, could lead to the failure of a wire bundle, and consequent adverse effects on other systems sharing the affected wire bundle.

Relevant Service Information

We have reviewed and approved Boeing Service Bulletins 747-25-3313, Revision 1, dated May 15, 2003 (for Model 747-200F and -400 series airplanes); 767-25-0335, dated November 7, 2002 (for Model 767-400ER series airplanes); and 777-25-0210, dated October 17, 2002 (for Model 777 series airplanes). The service bulletins describe procedures for replacing the frequency converter used to supply electrical power to utility outlets (for the galley, medical equipment, or personal computers) with a modified frequency converter, and any other specified actions, as applicable. The replacement involves removing the frequency converters, sending the frequency converter to the vendor (Avionic Instruments, Inc.) for rework, and installing the reworked frequency converter. The other specified actions involve performing a functional test, installing cautionary tags or placards on frequency converter switches/outlets in the cabin, and contacting the vendor for rework coordination, as applicable. Accomplishing the actions specified in the service bulletins is intended to adequately address the unsafe condition.

Boeing Service Bulletin 747-25-3313 refers to JAMCO Service Bulletin CAW74-25-1697, dated June 7, 2002, as an additional source of service information for procedures to remove and install certain galley frequency converters.

Concurrent Service Bulletin

For certain airplanes, Boeing Service Bulletin 777-25-0210 recommends prior or concurrent accomplishment of Monogram Systems Service Bulletin 872869-25-2098, dated May 1, 2002. The Monogram Systems service bulletin describes procedures for deactivating a galley frequency converter.

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 airplanes of this same type design. Therefore, we are proposing this AD, which would require replacing the frequency converter(s) used to supply power for utility outlets (for the galley, medical equipment, or personal computers) with modified frequency converter(s); and any other specified action and related concurrent actions, as necessary. The proposed AD would require you to use the applicable Boeing service information described previously to perform these actions.

Costs of Compliance

This proposed AD would affect about 147 airplanes worldwide. The following table provides the estimated costs for U.S. operators to comply with this proposed AD.

Estimated Costs

Boeing Model	Work hours	Average labor rate per hour	Cost per airplane	Number of U.S.-registered airplanes	Fleet cost
747-200F, -400 series airplanes	5 per converter (1 converter on each airplane)	$65	$325	0	$0
	5 per converter (2 converters on each airplane)	65	650	0	0
767-400ER series airplane	2 per airplanes	65	130	21	2,730
777 series airplanes	4 per airplane	65	260	8	2,080
Additional concurrent action for 777 series airplanes	1 per airplane	65	65	6	390

Currently, there are no affected Model 747-200F or -400 series airplanes on the U.S. Register. However, an affected airplane that is imported and placed on the U.S. Register in the future would be subject to the costs specified above for those airplanes.

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 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.

We prepared a regulatory evaluation of the estimated costs to comply with this proposed AD. See the ADDRESSES section for a location to examine the regulatory evaluation.

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.

§ 39.13

[Amended]

2. The FAA amends § 39.13 by adding the following new airworthiness directive (AD):

Boeing: Docket No. FAA-2004-19082; Directorate Identifier 2004-NM-79-AD.

Comments Due Date

(a) The Federal Aviation Administration (FAA) must receive comments on this AD action by October 28, 2004.

Affected ADs

(b) None.

Applicability

(c) This AD applies to the airplanes listed in Table 1 of this AD, certificated in any category:

Table 1.—Applicability

Boeing model—	As listed in Boeing service bulletin—
747-200F and -400 series airplanes	747-25-3313, Revision 1, dated May 15, 2003.
767-400ER series airplanes	767-25-0335, dated November 7, 2002.
777 series airplanes	777-25-0210, dated October 17, 2002.

Unsafe Condition

(d) This AD was prompted by a report that a hard short condition between the frequency converter's output and its downstream circuit breakers will produce a continuous current, which could cause the undersized output wiring to overheat. We are issuing this AD to prevent the overheating of the frequency converter's output wiring which could lead to the failure of a wire bundle, and consequent adverse effects on other systems sharing the affected wire bundle.

Compliance

(e) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.

Replacement

(f) Within 18 months after the effective date of this AD, replace the frequency converter(s) used to supply electrical power to utility outlets (for the galley, medical equipment, or personal computers) with modified frequency converter(s); and do other applicable specified actions; by doing all of the actions in the Accomplishment Instructions of the applicable service bulletin listed in Table 2 of this AD.

Table 2.—Applicable Service Bulletins

For model—	Use Boeing service bulletin—
747-200F and -400 series airplanes	747-25-3313, Revision 1, dated May 15, 2003.
767-400ER series airplanes	767-25-0335, dated November 7, 2002.
777 series airplanes	777-25-0210, dated October 17, 2002.

Note 1:

Boeing Service Bulletin 747-25-3313, Revision 1, dated May 15, 2003, refers to JAMCO Service Bulletin CAW74-25-1697, dated June 7, 2002, as an additional source of information for procedures to remove and install certain galley frequency converters.

Concurrent Service Bulletin

(g) For airplanes listed as Group 3 in the Effectivity of Boeing Service Bulletin 777-25-0210, dated October 17, 2002: Prior to or concurrently with the actions in Boeing Service Bulletin 777-25-0210, dated October 17, 2002, deactivate the galley frequency converter in accordance with the Accomplishment Instructions of Monogram Systems Service Bulletin 872869-25-2098, dated May 1, 2002.

Alternative Methods of Compliance (AMOCs)

(h) The Manager, Seattle Aircraft Certification Office (ACO), FAA, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19.

Issued in Renton, Washington, on September 1, 2004.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.