[Federal Register Volume 59, Number 80 (Tuesday, April 26, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-9989]


[[Page Unknown]]

[Federal Register: April 26, 1994]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 94-NM-50-AD; Amendment 39-8899; AD 94-09-10]

 

Airworthiness Directives; Boeing Model 757 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 757 series airplanes. This action 
requires revising the Non-Normal Procedures Section of the FAA-approved 
Airplane Flight Manual (AFM) to include procedures that will enable the 
flight crew to identify fuel system leaks and to take appropriate 
action to prevent further fuel loss. This amendment is prompted by 
reports that flight crew procedures related to fuel system leaks are 
not defined adequately in the FAA-approved AFM for these airplanes. The 
actions specified in this AD are intended to ensure that the flight 
crew is advised of the potential hazard related to fuel exhaustion due 
to undetected leakage, and the procedures necessary to address it.

DATES: Effective May 11, 1994.
    Comments for inclusion in the Rules Docket must be received on or 
before June 27, 1994.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 94-NM-50-AD, 1601 Lind Avenue SW., Renton, 
Washington 98055-4056.

FOR FURTHER INFORMATION CONTACT: Tamra J. Elkins, Aerospace Engineer, 
Propulsion Branch, ANM-140S, FAA, Transport Airplane Directorate, 
Seattle Aircraft Certification Office, 1601 Lind Avenue SW., Renton, 
Washington 98055-4056; telephone (206) 227-2669; fax (206) 227-1181.

SUPPLEMENTARY INFORMATION: Several in-service incidents have occurred 
on Model 757 series airplanes in which an engine fuel line has 
fractured and a significant fuel leak has occurred. These fuel leaks 
have occurred at locations within the engine fuel system upstream of 
the fuel flow transmitter. Under these circumstances, sufficient fuel 
may still be supplied to the engine, and the engine may operate 
normally. In these instances, the flight crew would receive no 
indication of abnormal fuel flow (i.e., fuel leakage) from the fuel 
flow meter. If the flight crew fails to detect a fuel leak, appropriate 
action would not be taken to prevent further fuel loss. This condition, 
if not corrected, could result in fuel exhaustion due to undetected 
fuel leakage.
    In light of this information, the FAA finds that certain procedures 
should be included in the FAA-approved Airplane Flight Manual (AFM) for 
Model 757 series airplanes to enable the flight crew to detect fuel 
system leaks and to take appropriate action. The FAA has determined 
that such procedures currently are not defined adequately in the AFM 
for these airplanes.
    Since an unsafe condition has been identified that is likely to 
exist or develop on other Boeing Model 757 series airplanes of the same 
type design, this AD is being issued to ensure that flight crews are 
advised of the potential hazard related to a significantly reduced or 
exhausted airplane fuel supply, and of the procedures to address it. 
This AD requires revising the Non-Normal Procedures Section of the AFM 
to include procedures that will enable the flight crew to identify fuel 
system leaks and to take appropriate action to prevent further fuel 
loss.
    This is considered to be interim action until final action is 
identified, at which time the FAA may consider further rulemaking.
    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 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 notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 94-NM-50-AD.'' The postcard will be date stamped and 
returned to the commenter.
    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 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 14 CFR part 
39 of the Federal Aviation Regulations as follows:

PART 39--AIRWORTHINESS DIRECTIVES

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

    Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 
106(g); and 14 CFR 11.89.


Sec. 39.13  [Amended]

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

94-09-10 Boeing: Amendment 39-8899. Docket 94-NM-50-AD.

    Applicability: All Model 757 airplanes, certificated in any 
category.
    Compliance: Required as indicated, unless accomplished 
previously.
    To ensure that the flight crew is advised of the potential 
hazard associated with fuel exhaustion due to undetected fuel 
leakage, and of the procedures necessary to address it, accomplish 
the following:
    (a) Within 60 days after the effective date of this AD, revise 
the Non-Normal Procedures Section of the FAA-approved Airplane 
Flight Manual (AFM) to include the following procedures, which will 
enable the flight crew to identify fuel system leaks and to take 
appropriate action to prevent further fuel loss. This may be 
accomplished by inserting a copy of this AD in the AFM.

``Flight Management Computer (FMC) Message Fuel QTY Error or Fuel 
Disagree

    Compare the Fuel Quantity Indicating System (FQIS) total fuel 
quantity and the FMC calculated fuel remaining (based on fuel flow) 
with estimated fuel usage data.
    If a fuel leak is suspected, close the crossfeed valve and turn 
off the center fuel pumps. Watch for any unusual decrease in fuel 
tank quantity and/or a fuel imbalance to determine if fuel is being 
lost.
    If an engine fuel leak is confirmed (either visually or by 
cockpit indications), shut down the affected engine to stop the leak 
and retain fuel. After shutdown, fuel from the remaining center, 
left, and right main tanks may be used for the operating engine. Use 
FQIS to determine fuel remaining.''
    (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 
Maintenance Inspector, who may add comments and then send it to the 
Manager, Seattle ACO.

    Note: 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 
Federal Aviation Regulations (FAR) 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 May 11, 1994.

    Issued in Renton, Washington, on April 20, 1994.
S. R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 94-9989 Filed 4-25-94; 8:45 am]
BILLING CODE 4910-13-U