05-170. Airworthiness Directives; Boeing Model 777-200 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 777-200 series airplanes. This proposed AD would require replacing the pressure switches on the override/jettison fuel pumps with new pressure switches, and replacing the ship side electrical connectors for the pressure switches on override/jettison fuel pumps with new connectors. This proposed AD is prompted by reports that the “FUEL LOW CENTER” message does not activate when the fuel level in the center tank is low. We are proposing this AD to prevent the fuel pumps in the center fuel tank from running dry and becoming a potential ignition source, which could result in a fuel tank explosion.

DATES:

We must receive comments on this proposed AD by February 22, 2005.

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 in person 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. This docket number is FAA-2004-19998; the directorate identifier for this docket is 2004-NM-224-AD.

FOR FURTHER INFORMATION CONTACT:

Technical information: Margaret Langsted, Aerospace Engineer, Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone [phone]; fax [phone].

Plain language information: Marcia Walters, [e-mail].

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 relevant written data, views, or arguments regarding this proposed AD. Send your comments to an address listed under ADDRESSES. Include “Docket No. FAA-2004-19998; Directorate Identifier 2004-NM-224-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 Web site, 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 can review DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78), or you can 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 on the Internet at http://dms.dot.gov, or 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

We have received reports indicating that the “FUEL LOW CENTER” message on the engine indication and crew alerting system (EICAS) did not come on during flight when the fuel quantity in the center tank was low (400 lbs or less), on several Boeing Model 777-200 series airplanes. A Boeing Model 777-200 series airplane was flight-tested to evaluate the problem. An analysis of the data collected indicated a problem with the design of the system tubing at the inlet of the center fuel tank pump. That design allows some residual fuel to collect near the pump impeller after the center tank fuel supply has been exhausted. As a result, the center tank pump produces sustained pressure above its low pressure switch range of 4-7 pounds per square inch gage (psig) when the main tank boost pumps supply back pressure against the center pump discharge check valve. Failure of the “FUEL LOW CENTER” message and the pump low pressure lights to come on when the center tank becomes empty, if not corrected, could result in the pumps running dry and becoming a potential ignition source in the fuel tank, which could consequently cause a fuel tank explosion.

Relevant Service Information

We have reviewed Boeing Special Attention Service Bulletin 777-28-0036, dated September 2, 2004. The service bulletin describes procedures for replacing the pressure switches on the override/jettison fuel pump with new pressure switches, and replacing the ship side electrical connectors for the pressure switches on the override/jettison fuel pumps with new connectors. Accomplishing the actions specified in the service information is intended to adequately address the unsafe condition.

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 accomplishing the actions specified in the service information described previously.

Costs of Compliance

There are about 61 airplanes of the affected design in the worldwide fleet. The following table provides the estimated costs for U.S. operators to comply with this proposed AD.

Estimated Costs

Action	Work hours	Average labor rate per hour	Parts	Cost per airplane	Number of U.S.-registered airplanes	Fleet cost
Replacement	3	$65	$13,430	$13,625	21	$286,125

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 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-2004-19998; Directorate Identifier 2004-NM-224-AD.

Comments Due Date

(a) The Federal Aviation Administration (FAA) must receive comments on this AD action by February 22, 2005.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Boeing Model 777-200 series airplanes, certificated in any category; as listed in Boeing Special Attention Service Bulletin 777-28-0036, dated September 2, 2004.

Unsafe Condition

(d) This AD was prompted by reports that the “FUEL LOW CENTER” message does not activate when the fuel level in the center tank is low. We are issuing this AD to prevent the fuel pumps in the center fuel tank from running dry and becoming a potential ignition source, which could result in a fuel tank explosion.

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 24 months after the effective date of this AD, replace the pressure switches on the override/jettison fuel pumps with new pressure switches, and replace the ship side electrical connectors for the pressure switches on the override/jettison fuel pumps with new connectors, in accordance with the Accomplishment Instructions of Boeing Special Attention Service Bulletin 777-28-0036, dated September 2, 2004.

Alternative Methods of Compliance (AMOCs)

(g) The Manager, Seattle Aircraft Certification Office, 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 December 27, 2004.

Kevin M. Mullin,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.