AD 94-15-03

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AD Number:
94-15-03
Document Type:
AD Final Rules
Docket Number:
94-NM-90-AD
Subject Heading:
Airworthiness Directives; Boeing Model 767 Series Airplanes
Subject:
Fuel System Leaks
Status:
Current
Citation:
(Federal Register: July 15, 1994 (Volume 59, Number 135))
Citation Publish Date:
07/15/1994
Effective Date:
08/01/1994
Make:
The Boeing Company
Model:
767-200 Series | 767-300 Series | 767-300F Series
Product Type:
Aircraft
Product Subtype:
Large Airplane
Affected AD:
Superseded AD:
Affected By:
Superseded By:
Service/Office:
Office of Primary Responsibility:
CFR Part Reference:
Part 39 (59 FR 36046 NO. 135 07/15/94)
Comments:
AIRWORTHINESS DIRECTIVES FINAL RULES: 94-15-03
CITATION:   [Federal Register: July 15, 1994 (Volume 59, Number 135)]

PAGE NUMBER:   [Page 36046]

DOCKET NUMBER:   94-NM-90-AD

AMENDMENT:   39-8974

AD NUMBER:   94-15-03

SUBJECT HEADING:   Airworthiness Directives; Boeing Model 767 Series Airplanes

ACTION:   Final rule; request for comments

SUMMARY:  
This amendment adopts a new airworthiness directive (AD) that is applicable to all Boeing Model 767 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 August 1, 1994. Comments for inclusion in the Rules Docket must be received on or before September 13, 1994.

ADDRESSES:  
Submit comments in triplicate to the Federal Aviation Administration (FAA),
Transport Airplane Directorate, ANM-103, Attention: Rules Docket No. 94-NM-90-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

FOR FURTHER INFORMATION CONTACT:  
Lanny Pinkstaff, Aerospace Engineer, Propulsion Branch, ANM-140S, FAA, Transport Airplane Directorate, Seattle Aircraft Certification Office, 1601 Lind Avenue SW., Renton, Washington 98055-4056; telephone (206) 227-2684; fax (206) 227-1181.

SUPPLEMENTARY INFORMATION:  
Several in-service incidents have occurred on Boeing Model 757 series airplanes in which an engine fuel line has cracked or 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.

Because the fuel system indication system and the AFM procedures of the Model 767 are similar to those of the Model 757, the potential for undetected fuel loss in the event of fractures of the fuel lines, and subsequent fuel leakage, exists for the Model 767.

In light of this information, the FAA finds that certain procedures should be included in the FAA-approved Airplane Flight Manual (AFM) for Model 767 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 767 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.

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 rule must submit a self-addressed, stamped postcard on which the following statement is made: "Comments to Docket Number 94-NM-90-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 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. App. 1354(a), 1421 and 1423; 49 U.S.C. 106(g); and 14 CFR 11.89. § 39.13 - [Amended]

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


REGULATORY TEXT:  
94-15-03 BOEING: Amendment 39-8974. Docket 94-NM-90-AD.

Applicability: All Model 767 series 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.

IN-FLIGHT ENGINE FUEL LEAK

If the Flight Management Computer (FMC) message, "FUEL DISAGREE - PROG 2/2", or "INSUFFICIENT FUEL", is displayed:

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, turn off the center wing tank pumps and close the crossfeed valves (tank-to-engine fuel feed configuration). 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 flight deck indications), shut down the affected engine to stop the leak and retain the remaining fuel. After shutdown of the affected engine, resume normal fuel management procedures. All remaining fuel can be used for the operating engine. Use the FQIS to determine the 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 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 August 1, 1994.

FOOTER: