AD Amdt-39-10136

[Federal Register Volume 62, Number 180 (Wednesday, September 17, 1997)]
[Rules and Regulations]
[Pages 48754-48755]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 97-24630]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-NM-239-AD; Amendment 39-10136; AD 97-19-15]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 767 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
is applicable to all Boeing Model 767 series airplanes. This action 
requires revising the Airplane Flight Manual (AFM) to include 
procedures that will ensure that the center tank fuel pumps are not 
operated with less than 1,000 pounds of fuel in the center tank. This 
amendment is prompted by a report indicating that a fuel pump failed 
due to damage to an impeller unit and pumping unit housing caused by a 
loose diffuser ring in the fuel pump assembly. The actions specified in 
this AD are intended to ensure the flight crew is advised of procedures 
that will ensure that the center tank fuel pumps are not operated with 
less than 1,000 pounds of fuel, which will prevent ignition of fuel 
vapors due to the generation of sparks and a potential ignition source 
inside the fuel tank caused by metal-to-metal contact during dry fuel 
pump operation.

DATES: Effective October 2, 1997.
    Comments for inclusion in the rules docket must be received on or 
before November 17, 1997.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 97-NM-239-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056.
    The information concerning this amendment may be obtained from or 
examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, 
SW., Renton, Washington.

FOR FURTHER INFORMATION CONTACT: Larry Reising, Aerospace Engineer, 
Propulsion Branch, ANM-140S, FAA, Transport Airplane Directorate, 
Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056; telephone (425) 227-2683; fax (425) 227-1181.

SUPPLEMENTARY INFORMATION: The FAA has received a report of failure of 
an override and jettison fuel pump on a Boeing Model 767 series 
airplane. Investigation revealed that the screws that attach the inlet 
diffuser assembly to the pumping unit housing became loose and were 
ingested into the fuel pump assembly. Loose screws caused the diffuser 
ring to become loose and contact the impeller, which damaged the 
impeller and pumping unit housing and caused the fuel pump to seize. 
During dry fuel pump operation, a loose diffuser ring also could cause 
metal-to-metal contact. This condition, if not corrected, could result 
in the generation of sparks and a potential ignition source inside the 
fuel tank.

Other Relevant Rulemaking

    The conditions described previously were addressed in AD 94-11-05, 
amendment 39-8921 (59 FR 27970, May 31, 1994), which is applicable to 
Boeing Model 767-200 and 767-300 series airplanes. That AD requires 
repetitive inspections of the pumping unit assembly on the override and 
jettison fuel boost pump assemblies to detect looseness of the screws 
that attach the inlet diffuser assembly to the pumping unit housing, 
and repair or replacement of the pumping unit assembly with a 
serviceable assembly, if necessary. For certain airplanes, that AD also 
provides for deactivation of the center wing fuel tank as an 
alternative to the repetitive inspections. The actions specified by 
that AD are intended to prevent the generation of sparks and a 
potential ignition source inside the fuel tank caused by metal-to-metal 
contact during dry fuel pump operation.

FAA's Findings

    Since the issuance of AD 94-11-05, an alternative method of 
compliance was granted that entailed fuel pump modifications, which 
alleviated the need for repetitive inspections of the fuel pump. 
However, the previously described report of failure of an override fuel 
pump occurred on a unit that had incorporated those modifications. The 
FAA has determined that, even if the override fuel pump fails, 
operation of the center tank fuel pumps with no less than 1,000 pounds 
of fuel will prevent ignition of fuel vapors due to the generation of 
sparks inside the fuel tank due to metal-to-metal contact. Therefore, 
the FAA has determined that a revision to the FAA-approved Airplane 
Flight Manual (AFM) for Model 767 series airplanes is necessary to 
ensure that the center tank fuel pumps are not operated with less than 
1,000 pounds of fuel in the center tank.

Explanation of the Requirements of the Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other Boeing Model 767 series airplanes of the same 
type design, this AD is being issued to prevent the generation of 
sparks and a potential ignition source inside the fuel tank caused by 
metal-to-metal contact during dry fuel pump operation. This AD requires 
revising the AFM to include procedures that will ensure that the center 
tank fuel pumps are not operated with less than 1,000 pounds of fuel in 
the center tank.

Interim Action

    This is considered to be interim action until final action is 
identified, at which time the FAA may consider further rulemaking.

Determination of Rule's Effective Date

    Since a situation exists that requires the immediate adoption of 
this regulation, it is found that notice and opportunity for prior 
public comment hereon are impracticable, and that good cause exists for 
making this amendment effective in less than 30 days.

Comments Invited

    Although this action is in the form of a final rule that involves 
requirements affecting flight safety and, thus, was not preceded by 
notice and an opportunity for public comment, comments are invited on 
this rule. Interested persons are invited to comment on this rule by 
submitting such written data, views, or arguments as they may desire. 
Communications shall identify the rules docket number and be submitted 
in triplicate to the address specified under the caption ADDRESSES. All 
communications received on or before the closing date for comments will 
be considered, and this rule may be amended in light of the comments 
received. Factual information that supports the commenter's ideas and 
suggestions is extremely helpful in evaluating the effectiveness of the 
AD action and determining whether additional rulemaking action would be 
needed.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the rule that might 
suggest a need to modify the rule. All comments

[[Page 48755]]

submitted will be available, both before and after the closing date for 
comments, in the Rules Docket for examination by interested persons. A 
report that summarizes each FAA-public contact concerned with the 
substance of this AD will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this rule must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 97-NM-239-AD.'' The postcard will be date stamped and 
returned to the commenter.

Regulatory Impact

    The regulations adopted herein will not have substantial direct 
effects 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, in 
accordance with Executive Order 12612, it is determined that this final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    The FAA has determined that this regulation is an emergency 
regulation that must be issued immediately to correct an unsafe 
condition in aircraft, and that it is not a ``significant regulatory 
action'' under Executive Order 12866. It has been determined further 
that this action involves an emergency regulation under DOT Regulatory 
Policies and Procedures (44 FR 11034, February 26, 1979). If it is 
determined that this emergency regulation otherwise would be 
significant under DOT Regulatory Policies and Procedures, a final 
regulatory evaluation will be prepared and placed in the rules docket. 
A copy of it, if filed, may be obtained from 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.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends part 39 of 
the Federal Aviation Regulations (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.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

97-19-15 Boeing: Amendment 39-10136. Docket 97-NM-239-AD.

    Applicability: All Model 767 series airplanes, certificated in 
any category.

    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 the generation of sparks and a potential ignition 
source inside the fuel tank caused by metal-to-metal contact during 
dry fuel pump operation, accomplish the following:
    (a) Within 14 days after the effective date of this AD, 
accomplish paragraphs (a)(1), (a)(2), (a)(3), and (a)(4) of this AD.
    (1) Revise the Limitations Section of the FAA-approved Airplane 
Flight Manual (AFM) to include the following procedures. This may be 
accomplished by inserting a copy of this AD in the AFM.
    If the center tank fuel pumps are to be used, there must be at 
least 5,000 pounds (2,267 kilograms) of fuel in the center tank 
prior to engine start.
    The center fuel pumps must be selected ``OFF'' at or greater 
than 1,000 pounds (453 kilograms) of fuel in the center tank. For 
airplanes not equipped with a center tank scavenge system, this 
1,000 pounds (453 kilograms) of center tank fuel must be considered 
unusable.

    Note: On all Model 767-200ER/300ER series airplanes and some 
Model 767-200/300 series airplanes, a scavenge system, operating 
with fuel pressure from the main wing tank pumps, will operate 
automatically to transfer any fuel remaining in the center tank to 
the main tanks. Fuel transfer begins when the main tanks are 
approximately half empty.

    (2) Revise the Limitations Section of the FAA-approved AFM 
entitled ``FUEL SYSTEM, FUEL USAGE II (fuel in center tank),'' to 
include the following procedures. This may be accomplished by 
inserting a copy of this AD in the AFM.
    ``Use the center tank fuel for all operations with all operable 
fuel pumps ``ON'' and the cross feed valve(s) closed until the 
center tank fuel quantity is 1,000 pounds (453 kilograms) or 
greater, then use FUEL USAGE I.
    Do not operate the center tank fuel pumps with less than 1,000 
pounds (453 kilograms) of fuel in the center tank.

    Note: The crossfeed valve(s) is open for minimum fuel operation, 
and may be opened to correct fuel imbalance.''

    (3) Revise the Normal Procedures Section of the FAA-approved AFM 
to include the following procedure. This may be accomplished by 
inserting a copy of this AD in the AFM.

``Use of Fuel From the Center Tank

    When the center tank approaches ``EMPTY'' during normal use or 
fuel transfer, select both center tank fuel pump switches ``OFF'' 
with the first occurrence of any of the following:
    <bullet> The center tank fuel reaches 1,000 pounds (453 
kilograms);
    <bullet> Either of the center tank fuel pump ``PRESS'' lights 
illuminate; or
    <bullet> Either the ``CTR L FUEL PUMP'' or ``CTR R FUEL PUMP'' 
EICAS message is displayed.''
    (4) Revise the Non-Normal Procedures Section of the FAA-approved 
AFM to include the following procedures. This may be accomplished by 
inserting a copy of this AD in the AFM.

``Center Tank Fuel Pump Faults

    A center tank fuel pump failure may have occurred if a fuel pump 
pressure light illuminates when there is ample fuel in the tank. If 
a fault is suspected, select the affected pump ``OFF'' and do not 
re-select ``ON.'' If the affected circuit breaker is tripped, do not 
reset. Select fuel crossfeed valve(s) ``OPEN.''
    Attempted operation of a faulted center tank pump could ignite 
fuel tank vapors in an empty or nearly empty tank.''

    (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, Transport Airplane Directorate. Operators shall 
submit their requests through an appropriate FAA Principal 
Operations Inspector, who may add comments and then send it to the 
Manager, Seattle ACO.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

    (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.
    (d) This amendment becomes effective on October 2, 1997.

    Issued in Renton, Washington on September 11, 1997.
James V. Devany,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 97-24630 Filed 9-16-97; 8:45 am]
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