AD 94-15-03

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 isextremely 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: