AD 98-26-04

This amendment supersedes an existing airworthiness directive (AD), applicable to certain Boeing Model 757 series airplanes, that currently requires an inspection of the engine fuel shutoff valves (spar valves) to detect leakage of fuel and to ensure that no leakage occurs when the valves are commanded to close. That amendment also requires an alignment procedure of the engine fuel shutoff valves, if necessary. This amendment expands the applicability of the existing AD. This amendment is prompted by additional reports that certain crossfeed valve assemblies and engine shutoff valve assemblies were improperly installed during manufacturing of the airplane. The actions specified in this AD are intended to prevent uncommanded fuel flow from the fuel tanks to the engine nacelle, which could result in reduced airplane fire protection in the event of a leak in the engine fuel line or a fire in the engine nacelle.

Final rule; request for comments.

98-26-04 BOEING: Amendment 39-10945. Docket 98-NM-336-AD. Supersedes AD 96-17-02, amendment 39-9710. \n\n\tApplicability: Model 757 series airplanes, as listed in Boeing Alert Service Bulletin 757-28A0045, Revision 1, dated November 19, 1998; certificated in any category. \n\n\tNOTE 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 (c)(1) 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. \n\n\tCompliance: Required as indicated, unless accomplished previously. \n\n\tTo prevent uncommanded fuel flow from the fuel tanks to the engine nacelle in the event of a leak in the engine fuel line or a fire in the engine nacelle, accomplish the following: \n\nRESTATEMENT OF REQUIREMENTS OF AD 96-17-02: \n\t(a)\tFor Model 757 series airplanes having line positions 478 through 699 inclusive: Within 60 days after August 28, 1996 (the effective date of AD 96-17-02, amendment 39-9710), perform an inspection to detect leakage of the fuel shutoff (spar) valves and verify that the valves do not leak when commanded to close, in accordance with Boeing Alert Service Bulletin 757-28A0045, dated July 30, 1996. \n\n\t\t(l)\tIf both fuel shutoff valves pass the inspection for leakage and the valves close when commanded, no further action is required by this AD. \n\n\t\t(2)\tIf either or both of the fuel shutoff valves do not pass the inspection for leakage: Prior to further flight,adjust the engine fuel shutoff valve(s) in accordance with Part III of the alert service bulletin and repeat the requirements of paragraph (a) of this AD. \n\nNEW REQUIREMENTS OF THIS AD: \n\t(b)\tFor Model 757 series airplanes, having line positions 700 through 710 inclusive, 712, 718, and 719: Within 60 days after the effective date of this AD, perform an inspection to detect leakage of the fuel shutoff (spar) valves and verify that the valves do not leak when commanded to close, in accordance with Boeing Alert Service Bulletin 757-28A0045, Revision 1, dated November 19, 1998. \n\n\t\t(l)\tIf both fuel shutoff valves pass the inspection for leakage and the valves close when commanded, no further action is required by this AD. \n\n\t\t(2)\tIf either or both of the fuel shutoff valves do not pass the inspection for leakage: Prior to further flight, adjust the engine fuel shutoff valve(s) in accordance with Part III of the alert service bulletin and repeat the requirements of paragraph (b) ofthis AD. \n\n\t(c)\t(1)\tAn 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. \n\n\t(c)\t(2)\tAlternative methods of compliance, approved previously in accordance with AD 96-17-02, amendment 39-9710, are approved as alternative methods of compliance with this AD. \n\n\tNOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO. \n\n\t(d)\tSpecial 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. \n\n\t(e)\tThe inspection and adjustment shall be done in accordance with Boeing Alert Service Bulletin 757-28A0045, dated July 30, 1996, or Boeing Alert Service Bulletin 757-28A0045, Revision 1, dated November 19, 1998. \n\n\t\t(1)\tThe incorporation by reference of Boeing Alert Service Bulletin 757-28A0045, Revision 1, dated November 19, 1998, is approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. \n\n\t\t(2)\tThe incorporation by reference of Boeing Alert Service Bulletin 757-28A0045, dated July 30, 1996, was approved previously by the Director of the Federal Register as of August 28, 1996 (61 FR 41953, August 13, 1996). \n\n\t\t(3)\tCopies may be obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-2207. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite700, Washington, DC. \n\n\t(f)\tThis amendment becomes effective on December 31, 1998.

On August 6, 1996, the FAA issued AD 96-17-02, amendment 39-9710 (61 FR 41953, August 13, 1996), applicable to certain Boeing Model 757 series airplanes. That AD requires an inspection of the engine fuel shutoff valves (spar valves) to detect leakage of fuel and to ensure that no leakage occurs when the valves are commanded to close. That AD also requires an alignment procedure of the engine fuel shutoff valves, if necessary. That action was prompted by reports that certain engine shutoff valve assemblies were improperly installed during manufacturing of the airplane. The actions required by that AD are intended to prevent uncommanded fuel flow from the fuel tanks to the engine nacelle, which could result in reduced aircraft fire protection in the event of a leak in the engine fuel line or a fire in the engine nacelle. \n\nActions Since Issuance of Previous Rule \n\n\tSince the issuance of that AD, the FAA has received information that certain fuel crossfeed valve assemblies, which are identical to the engine fuel shutoff valves referenced in AD 96-17-02, were installed improperly on one other Boeing Model 757 series airplane during manufacture. Upon further investigation, the manufacturer found several in-service airplanes that were assembled with uncertain processes may have engine fuel shutoff valves that were installed improperly. The line numbers on these airplanes were not included in the applicability of AD 96-17-02, although these airplanes may be subject to the same unsafe condition specified in that AD. Improperly installed crossfeed valve assemblies or engine fuel shutoff valve assemblies, if not corrected, could lead to uncommanded fuel flow from the fuel tanks to the engine nacelle, which could result in reduced airplane fire protection in the event of a leak in the engine fuel line or a fire in the engine nacelle. \n\nExplanation of Relevant Service Information \n\n\tAs a result of these new findings, the manufacturerissued, and the FAA has reviewed and approved, Boeing Alert Service Bulletin 757-28A0045, Revision 1, dated November 19, 1998. This revision is essentially identical to the procedures in the original issue but adds airplanes to the effectivity listing and additional instructions for operators with Pratt & Whitney-powered airplanes that have the optional interstage fuel pressure system. Accomplishment of the actions specified in the alert service bulletin is intended to adequately address the identified unsafe condition.\n\nExplanation of Requirements of Rule \n\n\tSince an unsafe condition has been identified that is likely to exist or develop on other airplanes of this same type design, this AD supersedes AD 96-17-02 to continue to require an inspection of the engine fuel shutoff valves (spar valves) to detect leakage of fuel and to ensure that no leakage occurs when the valves are commanded to close. This AD also continues to require an alignment procedure of the engine fuel shutoff valves, if necessary. This new AD revises the applicability of the existing AD to include airplanes that are subject to the same unsafe condition. \n\nDetermination of Rule's Effective Date \n\n\tSince 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. \n\nComments Invited \n\n\tAlthough 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 onor 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. \n\n\tComments 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. \n\n\tCommenters 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 98-NM-336-AD." The postcard will be date stamped and returned to the commenter. \n\nRegulatory Impact \n\n\tThe 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. \n\n\tThe 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." \n\nList of Subjects in 14 CFR Part 39 \n\n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. \nAdoption of the Amendment \n\n\tAccordingly, 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 \n\t1. The authority citation for part 39 continues to read as follows: Authority: 49 U.S.C. 106(g), 40113, 44701. § 39.13 (Amended) \n\t2. Section 39.13 is amended by removing amendment 39-9710 (61 FR 41953, August 13, 1996), and by adding a new airworthiness directive (AD), amendment 39-10945, to read as follows: