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Proposed Rule

Airworthiness Directives; Boeing Model 767 Series Airplanes

Document Details

Information about this document as published in the Federal Register.

Published Document

This document has been published in the Federal Register. Use the PDF linked in the document sidebar for the official electronic format.

Start Preamble

AGENCY:

Federal Aviation Administration (FAA), Department of Transportation (DOT).

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to adopt a new airworthiness directive (AD) for all Boeing Model 767 series airplanes. This proposed AD would require an inspection of each main tank fuel boost pump for the presence of a pump shaft flame arrestor, and if the flame arrestor is missing, replacement of that pump with a pump having a pump shaft flame arrestor. This proposed AD would also require repetitive measurements of the flame arrestor's position in the pump, and corrective actions if necessary. This proposed AD is prompted by reports that certain fuel boost pumps may not have flame arrestors installed in the pump shaft. We have also received reports that the pin that holds the flame arrestor in place can break due to metal fatigue. We are proposing this AD to prevent the possible migration of a flame from a main tank fuel boost pump inlet to the vapor space of that fuel tank, and consequent ignition of fuel vapors, which could result in a fire or explosion should the pump inlets become uncovered.

DATES:

We must receive comments on this proposed AD by April 1, 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: (202) 493-2251.
  • 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. Start Printed Page 7679

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-2005-20351; the directorate identifier for this docket is 2003-NM-269-AD.

Start Further Info

FOR FURTHER INFORMATION CONTACT:

Bernie Gonzalez, Aerospace Engineer, Propulsion Branch, ANM-140S, FAA, Transport Airplane Directorate, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 917-6498; fax (425) 917-6590.

End Further Info End Preamble Start Supplemental Information

SUPPLEMENTARY INFORMATION:

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-2005-20351; Directorate Identifier 2003-NM-269-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 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.

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 (800) 647-5227) 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 that certain fuel boost pumps for the main fuel tanks do not have pump shaft flame arrestors installed. While the affected fuel boost pumps were installed on certain Boeing Model 767 series airplanes, the pumps may have been transferred to other airplanes during operator maintenance. Therefore, all Boeing Model 767 airplanes may be affected.

We have also received reports that the roll pin that holds the flame arrestor in the proper position in the fuel boost pump shaft can break due to metal fatigue. If the pin breaks, the pin and the flame arrestor can drop down the pump shaft into the reprime/vapor removal portion of the pump. The ingestion of the metal pieces created by the broken pin may produce a sparking condition and consequent ignition of vapor if present. The pump shaft flame arrestor is part of the explosion-proof enclosure of the fuel pump. This flame arrestor's function is to contain an internal pump explosion and prevent any flame from reaching the fuel tank via the pump inlet. If the flame arrestor is missing or loose, the pump is no longer explosion proof. In this condition, if the pump inlet is uncovered such that the pump runs dry, the fuel tank has no protection from flame egress due to an ignition within the pump. Such conditions may exist during ground defueling of the airplane fuel tanks and during abnormal operating conditions involving a low quantity of fuel in the tank. During low fuel operation one or more fuel pumps may experience intermittent dry operation for sufficient periods of time to permit vapor ignition within the pump. This condition, if not corrected, could result in the migration of a flame from a main tank fuel boost pump inlet to the vapor space of that fuel tank, and consequent ignition of fuel vapors, which could result in a fire or explosion.

Relevant Service Information

We have reviewed Boeing Alert Service Bulletins 767-28A0077 (for Model 767-200, -300, and -300F series airplanes) and 767-28A0081 (for Model 767-400ER series airplanes), both Revision 1, both dated July 8, 2004, which describe procedures for inspecting each main tank fuel boost pump to determine if the pin and flame arrestor are installed, repetitively measuring the position of the flame arrestor in the pump, and corrective actions. The corrective actions include installing serviceable boost pumps. The Boeing alert service bulletins reference Hamilton Sundstrand Service Bulletin 5006003-28-2, dated October 25, 2002, as an additional source of service information for doing the inspections and corrective actions. The procedures in the Hamilton Sundstrand service bulletin include:

  • Removing the pumping unit assemblies from the main fuel tank boost pumps.
  • Measuring the distance from the impeller end of the shaft to the flame arrestor (finned plug) in the pumping unit assemblies.
  • Testing certain pumping unit assemblies.
  • Marking the identification plates of each pumping unit assembly with the symbol “28-2.”
  • Reinstalling the pumping unit assemblies into the fuel boost pumps.

If the measurement is greater than the limit specified in the Hamilton Standard service bulletin, that service bulletin specifies to return the affected pumping unit assembly to a repair shop for replacement of the pin and flame arrestor.

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 a detailed inspection of each main tank fuel boost pump to determine if a flame arrestor is installed, repetitive measurements of the position of the flame arrestor in the pump, and corrective actions if necessary. The proposed AD would require you to use the service information described previously, except as discussed under “Difference Between the Proposed AD and Service Information.”

Difference Between the Proposed AD and Service Information

Operators should note that, although the Hamilton Sundstrand service bulletin specifies to return main tank fuel boost pumps with damaged, broken, or out-of-position flame arrestors to a repair shop, that action is not required by this proposed AD. Start Printed Page 7680

Clarification of Inspection Terminology

Boeing Alert Service Bulletins 767-28A0077 and 767-28A0081, both Revision 1, specify to do an inspection of each main tank fuel boost pump for the presence or integrity of the flame arrestor as specified in Hamilton Sundstrand Service Bulletin 5006003-28-2, dated October 25, 2002. This proposed AD requires a detailed inspection of each main tank fuel boost pump for the presence of the flame arrestor. Note 2 has been included in this proposed AD to define this type of inspection.

The inspection of the integrity of the flame arrestor is referred to as a “check” in the Hamilton Sundstrand service bulletin. Instead of referring to this action as a check, this proposed AD uses the term “measurement.”

Interim Action

We consider this proposed AD interim action. If final action is later identified, we may consider further rulemaking then.

Costs of Compliance

This proposed AD would affect about 915 airplanes worldwide, and 400 airplanes of U.S. registry. The following table provides the estimated costs for U.S. operators to comply with this proposed AD.

Estimated Costs

ActionWork hoursAverage labor rate per hourPartsCost per airplaneNumber of U.S.-registered airplanesFleet cost
Inspection of flame arrestor presence/position, per inspection cycle5$65None$325, per inspection cycle400$130,000

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.

Start List of Subjects

List of Subjects in 14 CFR Part 39

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The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows:

Start Part

PART 39—AIRWORTHINESS DIRECTIVES

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

Start Authority

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

End Authority
[Amended]

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

Boeing: Docket No. FAA-2005-20351; Directorate Identifier 2003-NM-269-AD.

Comments Due Date

(a) The Federal Aviation Administration (FAA) must receive comments on this AD action by April 1, 2005.

Affected ADs

(b) None.

Applicability

(c) This AD applies to all Boeing Model 767 series airplanes, certificated in any category.

Unsafe Condition

(d) This proposed AD is prompted by reports that certain fuel boost pumps may not have flame arrestors installed in the pump shaft. We have also received reports that the pin that holds the flame arrestor in place can break due to metal fatigue. We are issuing this AD to prevent the possible migration of a flame from a main tank fuel boost pump inlet to the vapor space of that fuel tank, and consequent ignition of fuel vapors, which could result in a fire or explosion should the pump inlets become uncovered.

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.

Service Bulletin References

(f) The term “alert service bulletin,” as used in this AD, means the Accomplishment Instructions of Boeing Alert Service Bulletins 767-28A0077 (for Model 767-200, -300, and -300F series airplanes) and 767-28A0081 (for Model 767-400ER series airplanes), both Revision 1, both dated July 8, 2004; as applicable.

Note 1:

The Boeing alert service bulletins reference Hamilton Sundstrand Service Bulletin 5006003-28-2, dated October 25, 2002, as an additional source of service information for accomplishment of the inspection and corrective actions. Although the Hamilton Sundstrand service bulletin specifies to return main tank fuel boost pumps with damaged, broken, or out-of-position flame arrestors to a repair shop, that action is not required by this AD.

Inspection for Presence/Position of Flame Arrestor in Main Tank Fuel Boost Pumps

(g) Prior to the accumulation of 15,000 total flight hours, or within 365 days after the effective date of this AD, whichever is later: Do a detailed inspection of each main tank fuel boost pump to determine if the pump shaft flame arrestor is installed, a Start Printed Page 7681measurement of the flame arrestor's position in the pump, and any applicable corrective actions, by accomplishing all of the actions in the applicable alert service bulletin. Repeat the measurement of the flame arrestor's position in the pump thereafter at intervals not to exceed 6,000 flight hours or 24 months, whichever is first. Any applicable corrective actions must be done before further flight.

Note 2:

For the purposes of this AD, a detailed inspection is: “An intensive examination of a specific item, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at an intensity deemed appropriate. Inspection aids such as mirror, magnifying lenses, etc., may be necessary. Surface cleaning and elaborate procedures may be required.”

Note 3:

There is no terminating action available at this time for the repetitive inspections required by paragraph (g) of this AD.

Parts Installation

(h) As of the effective date of this AD, no main tank fuel boost pump may be installed on any airplane unless it has been inspected, and any applicable corrective action performed, in accordance with the requirements of this AD.

Alternative Methods of Compliance (AMOCs)

(i) 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.

Start Signature

Issued in Renton, Washington, on February 6, 2005.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.

End Signature End Part End Supplemental Information

[FR Doc. 05-2839 Filed 2-14-05; 8:45 am]

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