AD 97-10-11

This amendment adopts a new airworthiness directive (AD) that is applicable to all Boeing Model 777 series airplanes. This action requires repetitive testing of the engine fire shutoff switch (EFSS) to determine that the override mechanism and the switch handle are operational, and replacement of the EFSS, if necessary. This action also requires, for certain airplanes, installation of a collar on a specific circuit breaker of the standby power management panel, and installation of placards to advise the flightcrew that the override mechanism must be pushed in order to pull the fire switch. This amendment is prompted by a report indicating that a solenoid and an override mechanism of the EFSS were not operational due to overheating of the solenoid. The actions specified in this AD are intended to prevent damage to the EFSS solenoid and to the override mechanism, and consequent failure of the EFSS due to overheating of the solenoid; such failure of the EFSS could result in the inability of the flightcrew to discharge the fire extinguishing agent in the event of an engine fire.

Final rule; request for comments

97-10-11 BOEING: Amendment 39-10023. Docket 97-NM-90-AD. \n\n\tApplicability: All Model 777 series airplanes, 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 otherwise 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) 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 damage to the engine fire shutoff switch (EFSS) solenoid and to the override mechanism, and consequent failure of the EFSS, which could result in the inability of the flightcrew to discharge the fire extinguishing agent in the event of an engine fire, accomplish the following:\n\n\t(a)\tFor all airplanes: Within 14 days after the effective date of this AD, perform a test of the EFSS of both the left- and right-hand engines to determine if the override mechanism and the switch handle are operational, in accordance with Boeing Alert Service Bulletin 777-26A0012, dated May 1, 1997. \n\n\t\t(1)\tIf the override mechanism and the switch handle of the EFSS are operational, prior to further flight, accomplish the requirements of paragraph (a)(1)(i) or (a)(1)(ii) of this AD, as applicable, in accordance with the alert service bulletin. \n\n\t\t\t(i)\tFor Group 1 airplanes identified in the alert service bulletin: Install a collar on circuit breaker C26612 of panel P310 of the standby power management panel. Followingaccomplishment of this installation, prior to further flight, install placards near the EFSS of both engines and near the auxiliary power unit (APU) EFSS to advise the flightcrew that the override mechanism must be pushed in order to pull the fire switch. \n\n\t\t\t(ii)\tFor Group 2 airplanes identified in the alert service bulletin: Ensure that a collar is installed on circuit breaker C26612 of panel P310 of the standby power management panel. If a collar is not installed, prior to further flight, install a collar on circuit breaker C26612 of panel P310 of the standby power management panel. \n\n\t\t(2)\tIf the override mechanism or the switch handle of the EFSS is not operational, prior to further flight, replace the EFSS with a new or serviceable EFSS, in accordance with the alert service bulletin. \n\n\t(b)\tFor all airplanes: Repeat the requirements of paragraph (a) of this AD thereafter at intervals not to exceed 500 flight hours. \n\n\t(c)\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\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 actions shall be done in accordance with Boeing Alert Service Bulletin 777-26A0012, dated May 1, 1997. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a)and 1 CFR part 51. Copies 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., suite 700, Washington, DC. \n\n\t(f)\tThis amendment becomes effective on May 27, 1997.

The FAA has received a report indicating that a solenoid and an override mechanism of the engine fire shutoff switch (EFSS) were not operational. Investigation revealed that an overheating condition in the solenoid damaged the solenoid and the override mechanism of the EFSS. Further investigation revealed that the overheating condition of the solenoid may be caused when power is applied to the EFSS solenoid for long periods of time, such as when the airplane is on the ground with the power on and the engine fuel control switch is in the "Cutoff" position. Damage to the EFSS solenoid and to the override mechanism due to overheating of the solenoid could result in failure of the EFSS. Such failure, if not corrected, could result in the inability of the flightcrew to discharge the fire extinguishing agent in the event of an engine fire. \n\nExplanation of Relevant Service Information \n\n\tThe FAA has reviewed and approved Boeing Alert Service Bulletin 777-26A0012, dated May 1, 1997, which describes procedures for repetitive testing of the EFSS of both the left- and right-hand engines to determine if the override mechanism and the switch handle are operational, and replacement of the EFSS, if necessary. For any airplanes on which a collar on circuit breaker C26612 of panel P310 of the standby power management panel has not been installed, the alert service bulletin also describes procedures to perform that installation, and to install placards near the EFSS of both engines and near the auxiliary power unit (APU) EFSS to advise the flightcrew that the override mechanism must be pushed in order to pull the fire switch. Installation of the collar on circuit breaker C26612 of panel P310, which is the circuit breaker that supplies power to the EFSS solenoids, will prevent damage to the EFSS due to overheating of the solenoid. \n\nExplanation of the Requirements of the Rule\n\n\tSince an unsafe condition has been identified that is likely toexist or develop on other Boeing Model 777 series airplanes of the same type design, this AD is being issued to prevent damage to the EFSS solenoid and to the override mechanism and consequent failure of the EFSS due to overheating of the solenoid; such failure could result in the inability of the flightcrew to discharge the fire extinguishing agent in the event of an engine fire. This AD requires repetitive testing of the EFSS of both the left- and right-hand engines to determine if the override mechanism and the switch handle are operational, and replacement of the EFSS, if necessary. For certain airplanes, this AD requires installation of a collar on circuit breaker C26612 of panel P310 of the standby power management panel, and installation of placards near the EFSS of both engines and near the APU EPSS to advise the flightcrew that the override mechanism must be pushed in order to pull the fire switch. The actions are required to be accomplished in accordance with the alert service bulletin described previously.\n \nInterim Action \n\n\tThis is considered to be interim action until final action is identified, at which time the FAA may consider further rulemaking. \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 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.\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 followingstatement is made: "Comments to Docket Number 97-NM-90-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 itis 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. \n\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:\n\n PART 39 - AIRWORTHINESS DIRECTIVES\n \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 adding the following new airworthiness directive: