AD 94-01-10 R1

This amendment revises an existing airworthiness directive (AD), applicable to certain Boeing Model 757-200 and -200PF series airplanes, that currently requires inspections, adjustments, and functional checks of the engine thrust reverser system; and modification of the engine thrust reverser directional control valve. The existing AD also requires installation of an additional thrust reverser locking feature and periodic functional tests of the locking feature following installation. That AD was prompted by results of a safety review of the thrust reverser system on these airplanes. The actions specified by that AD are intended to prevent deployment of a thrust reverser in flight and subsequent reduced controllability of the airplane. This action reduces the applicability of the existing AD. \n\nDATES: Effective September 18, 2003.\n\n\tThe incorporation by reference of certain publications, as listed in the regulations, was approved by the Director of the Federal Register asof March 3, 1994 (59 FR 4558, February 1, 1994). The incorporation by reference of certain other publications, as listed in the regulations, was approved previously by the Director of the Federal Register as of September 16, 1991 (56 FR 46725, September 16, 1991). (The document numbers of these certain publications were\ncited erroneously in the September 16, 1991, issue of the Federal Register, as listed in the regulations.)

Final rule.

AD 94-01-10 R1 Boeing: Amendment 39-13247. Docket 2001-NM-341-AD. Revises AD 94-01-10, Amendment 39-8792. \n\n\tApplicability: Model 757-200 and -200PF series airplanes equipped with Pratt and Whitney PW2000 series engines, 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 (g)(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 deployment of a thrust reverser in flight and subsequent reduced controllability of the airplane, accomplish the following: \n\nInspections/Adjustments/Functional Checks/Modification \n\n\t(a) For airplanes having line numbers prior to 442: Within 14 days after September 16, 1991 (the effective date of AD 91-20-09, amendment 39-8043), accomplish either paragraph (a)(1) or (a)(2) of this AD. \n\n\t(1) Accomplish both paragraphs (a)(1)(i) and (a)(1)(ii) of this AD: \n\n\t(i) Inspect the thrust reverser Directional Control Valve (DCV) assemblies of both engines to determine the solenoid-driven pilot valve's part number, in accordance with Boeing Alert Service Bulletin 757-78A0027, dated September 9, 1991. \n\n\t(A) If any DCV has a suspect pilot valve as specified in the service bulletin, prior to further flight, replace the DCV with a DCV that has a part number of a non-suspect solenoid-driven pilot valve, in accordance with the service bulletin. \n\n\t(B) If a DCV has a non-suspect solenoid-driven pilot valve as specified in the service bulletin, that pilot valve does not need to be replaced. \n\n\t(ii) Perform all tests and inspections of the engine thrust reverser control and indication system on both engines in accordance with Boeing Service Bulletin 757-78-0025, dated September 9, 1991. Prior to further flight, correct any discrepancy found in accordance with the service bulletin. \n\n\t(2) Accomplish paragraph (a)(1) of this AD on one engine's thrust reverser and deactivate the other engine's thrust reverser, in accordance with Section 78-31-1 of Boeing Document D630N002, "Boeing 757 Dispatch Deviation Guide," Revision 8, dated January 15, 1991. \n\n\t(b) For airplanes having line numbers prior to 442: Within 24 days after September 16, 1991, the requirements of paragraph (a)(1) of this AD must be accomplished on both engines' thrust reverser systems. \n\n\t(c) For all airplanes: Perform all tests and inspections of the engine thrust reverser control and indication system on both engines in accordance with Boeing Service Bulletin 757-78-0025, dated September 9, 1991, as specified in paragraph (c)(1) or (c)(2) of this AD, as applicable. Correct any discrepancy before further flight in accordance with the service bulletin. \n\n\t(1) For airplanes having line numbers prior to 442: Repeat the tests and inspections (these tests and inspections are specified in paragraph (a)(1)(ii) of this AD) at intervals not to exceed 3,000 flight hours, and prior to further flight following any maintenance that disturbs the thrust reverser control system. \n\n\t(2) For airplanes having line numbers 442 and subsequent: Perform the tests and inspections within 3,000 flight hours after the effective date of this AD. Repeat the tests and inspections at intervals not to exceed 3,000 flight hours, and prior to further flight following any maintenance that disturbs the thrust reverser control system. \n\nInstallation/Functional Test \n\n\t(d) For airplanes having line numbers prior to 442: Within 5 years after March 3, 1994 (the effective date of AD 94-01-10, amendment 39-8792), install an additional thrust reverser system locking feature (sync lock installation), in accordance with Boeing Service Bulletin 757-78-0028, Revision 1, dated October 29, 1992; or Revision 2, dated January 14, 1993. \n\n\t(e) Within 1,000 hours' time-in-service after installing the sync lock required by paragraph (d) of this AD (either in production or by retrofit), or within 1,000 hours' time-in-service after March 3, 1994, whichever occurs later; and thereafter at intervals not to exceed 1,000 hours' time-in-service: Perform functional tests of the sync lock in accordance with the "Thrust Reverser Sync Lock Integrity Test" procedures specified below. If any discrepancy is found during any test, prior to further flight, correct it in accordance with procedures described in the Boeing 757 Maintenance Manual. \n\n"THRUST REVERSER SYNC LOCK INTEGRITY TEST \n\n1. General \n\nA. Use this procedure to test the integrity of the thrust reverser sync locks. \n\n2. Thrust Reverser Sync Lock Test \n\nA. Prepare for the Thrust Reverser Sync Lock Test. \n\t(1) Open the AUTO SPEEDBRAKE circuit breaker on the overhead circuit breaker panel, P11. \n\n\t(2) Do the steps that follow to supply power to the thrust reverser system: \n\n\t(a) Make sure the thrust levers are in the idle position. \n\nCAUTION: DO NOT EXTEND THE THRUST REVERSER WHILE THE CORE COWL PANELS ARE OPEN. DAMAGE TO THE THRUST REVERSER AND CORE COWL PANELS CAN OCCUR. \n\n\t(b) Make sure the thrust reverser halves are closed. \n\n\t(c) Make sure the core cowl panels are closed. \n\n\t(d) Put the EEC MAINT POWER switch or the EEC POWER L and EEC POWER R switches to the ALTN position. \n\n\t(e) For the left engine: \n\n\t(1) Put the EEC MAINT CHANNEL SEL L switch to the AUTO position. \n\n\t(2) Put the L ENG fire switch to the NORM position.(f) For the right engine: \n\n\t(1) Put the EEC MAINT CHANNEL SEL R switch to the AUTO position. \n\n\t(2) Put the R ENG fire switch to the NORM position. \n\n\t(g) Make sure the EICAS circuit breakers (6 locations) are closed. \n\nWARNING: THE THRUST REVERSER WILL AUTOMATICALLY RETRACT IF THE ELECTRICAL POWER TO THE EEC/THRUST REVERSER CONTROL SYSTEM IS TURNED OFF OR IF THE EEC MAINT POWER SWITCH IS MOVED TO THE NORM POSITION. THE ACCIDENTAL OPERATION OF THE THRUST REVERSER CAN CAUSE INJURY TO PERSONS OR DAMAGE TO EQUIPMENT CAN OCCUR. \n\n\t(h) Make sure these circuit breakers on the main power distribution panel, P6, are closed: \n\n\t(1) FUEL COND CONT L \n\n\t(2) FUEL COND CONT R \n\n\t(3) T/L INTERLOCK L \n\n\t(4) T/L INTERLOCK R \n\n\t(5) LEFT T/R SYNC LOCK \n\n\t(6) RIGHT T/R SYNC LOCK \n\n\t(7) L ENG ELECTRONIC ENGINE CONTROL ALTN PWR (if installed) \n\n\t(8) R ENG ELECTRONIC ENGINE CONTROL ALTN PWR (if installed) \n\n\t(i) Make sure these circuit breakers on the overhead circuit breaker panel, P11, are closed: \n\n\t(1) AIR/GND SYS 1 \n\n\t(2) AIR/GND SYS 2 \n\n\t(3) LANDING GEAR POS SYS 1 \n\n\t(4) LANDING GEAR POS SYS 2 \n\n\t(j) For the left engine, make sure these circuit breakers on the P11 panel are closed: \n\n\t(1) LEFT ENGINE PDIU \n\n\t(2) LEFT ENGINE THRUST REVERSER CONT/SCAV PRESS \n\n\t(3) LEFT ENGINE ELECTRONIC ENGINE CONTROL ALTN PWR (if installed) \n\n\t(4) LEFT ENGINE THRUST REVERSER PRI CONT \n\n\t(5) LEFT ENGINE THRUST REVERSER SEC CONT \n\n\t(k) For the right engine, make sure these circuit breakers on the P11 panel are closed: \n\n\t(1) RIGHT ENGINE PDIU \n\n\t(2) RIGHT ENGINE THRUST REVERSER CONT/SCAV PRESS \n\n\t(3) RIGHT ENGINE ELECTRONIC ENGINE CONTROL ALTN PWR (if installed) \n\n\t(4) RIGHT ENGINE THRUST REVERSER PRI CONT \n\n\t(5) RIGHT ENGINE THRUST REVERSER SEC CONT \n\n\t(l) Supply electrical power\n. \n\t(m) Remove the pressure from the left (right) hydraulic system. B. Do the Thrust Reverser Sync Lock Test. \n\n\t(1) Move and hold the manual unlock lever on the center actuator on both thrust reverser sleeves to the unlock position. \n\n\t(2) Make sure the thrust reverser sleeves did not move. \n\n\t(3) Move the left (right) reverser thrust lever up and rearward to the idle detent position. \n\n\t(4) Make sure both thrust reverser sleeves move aft (approximately 0.15 to 0.25 inch). \n\n\t(5) Release the manual unlock lever on the center actuators. \n\nWARNING: MAKE SURE ALL PERSONS AND EQUIPMENT ARE CLEAR OF THE AREA AROUND THE THRUST REVERSER. WHEN YOU APPLY HYDRAULIC PRESSURE THE THRUST REVERSER WILL EXTEND AND CAN CAUSE INJURIES TO PERSONS OR DAMAGE TO EQUIPMENT. \n\n\t(6) Pressurize the left (right) hydraulic system. \n\n\t(7) Make sure the thrust reverser extends. \n\n\t(8) Move the left (right) reverser thrust lever to the fully forward and down position to retract the thrust reverser. C. Put the Airplane Back to its Usual Condition. \n\n\t(1) Remove hydraulic pressure. \n\n\t(2) Close the left and right fan cowls. \n\n\t(3) Close the AUTO SPEEDBRAKE circuit breaker on the P11 panel. \n\n\t(4) Remove electrical power if it is not necessary. \n\n\t(5) Return the EEC MAINT POWER switch or the EEC POWER L and EEC POWER R switches to the NORMAL position. D. Repeat the Thrust Reverser Sync Lock Test on the other engine." \n\n\t(f) Installation of the sync lock, as required by paragraph (d) of this AD, constitutes terminating action for the requirements of paragraphs (a) through (c) of this AD. \n\nAlternative Methods of Compliance \n\n\t(g)(1) 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. \n\n\t(2) Alternative methods of compliance, approved previously in accordance with AD 91-20-09, amendment 39-8043; and AD 94-01-10, amendment 39-8792; are approved as alternative methods of compliance with the requirements of 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\nSpecial Flight Permits \n\n\t(h) 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. \n\nIncorporation by Reference \n\n\t(i) Except as otherwise required by this AD, the actions shall be done in accordance with Boeing Alert Service Bulletin 757- 78A0027, dated September 9, 1991; Boeing Service Bulletin 757-78- 0025, dated September 9, 1991; Boeing Document D630N002, "Boeing 757 Dispatch Deviation Guide," Revision 8, dated January 15, 1991; and Boeing Service Bulletin 757-78-0028, Revision 1, dated October29, 1992, or Boeing Service Bulletin 757-78-0028, Revision 2, dated January 14, 1993; as applicable. \n\n\t(1) The incorporation by reference of Boeing Service Bulletin 757-78-0028, Revision 1, dated October 29, 1992; and Boeing Service Bulletin 757-78-0028, Revision 2, dated January 14, 1993; was approved previously by the Director of the Federal Register as of March 3, 1994 (59 FR 4558, February 1, 1994). \n\n\t(2) The incorporation by reference of Boeing Alert Service Bulletin 757-78A0027, dated September 9, 1991; Boeing Service Bulletin 757-78-0025, dated September 9, 1991; and Boeing Document D630N002, "Boeing 757 Dispatch Deviation Guide," Revision 8, dated January 15, 1991; was approved previously by the Director of the Federal Register as of September 16, 1991 (56 FR 46725, September 16, 1991). (The document number of Boeing Alert Service Bulletin 757-78A0027, dated September 9, 1991, was cited erroneously in the September 16, 1991, issue of the Federal Register as "757- 78H0027." The document number of Boeing Service Bulletin 757-78- 0025, dated September 9, 1991, was also cited erroneously in the September 16, 1991, issue of the Federal Register as "757-0025.") \n\n\t(3) Copies of the service documents 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\nEffective Dates \n\n\t(j) This amendment becomes effective on September 18, 2003.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by revising AD 94-01-10, amendment 39-8792 (59 FR 4558, February 1, 1994), which is applicable to certain Boeing Model 757 series airplanes, was published in the Federal Register on October 8, 2002 (67 FR 62654). The action proposed to continue to require inspections, adjustments, and functional checks of the engine thrust reverser system; modification of the engine thrust reverser directional control valve; and installation and periodic functional tests of an additional thrust reverser locking feature. The action also proposed to reduce the applicability of the existing AD. \n\nComments \n\n\tInterested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comments received. \n\nSupport for the AD \n\n\tTwo commenters support the AD, as proposed. \n\nRequest To Issue AD as a Correction \n\n\tTwo commentersrequest that the proposed AD be issued to correct rather than revise AD 94-01-01. The commenters suggest that a correction in this case would be more appropriate and would minimize record keeping by the operators. One of the commenters states that, "(I)f a new AD number or a revision to the existing AD is issued, (the operator) will be required to revise all of (the operator's) AD implementation and record keeping documentation at a significant cost to (the) airline. If a correction to the original AD is issued, no document changes will be necessary." \n\n\tThe FAA disagrees with the commenters' characterization of the AD revision process. First, a correction to an AD is used primarily for nonsubstantive changes including clarification of ambiguous language in the existing AD. A correction to an AD does not receive a new AD number. A revision to an AD is used to make changes such as reducing the applicability for this AD. A revision of an AD is usually less complicated for operators totrack because the compliance documentation need include only the AD number regardless of the revision number. This final rule will be issued as a revision to the existing AD, as proposed. \n\nRequest for Clarification of Existing Requirements \n\n\tOne commenter questions whether an aircraft could be dispatched with the thrust reversers active after failing the thrust reverser sync lock integrity test but passing subsequent testing in accordance with Boeing Service Bulletin 757-78-0025 or Airplane Maintenance Manual 78- 31-00/501. \n\n\tParagraph (e) of AD 94-01-10 requires that any discrepancy found during any test required by that AD be corrected before further flight in accordance with the Boeing 757 Maintenance Manual. Therefore, any failures experienced during the integrity test must be appropriately addressed and resolved prior to dispatch of the airplane with the thrust reverser system active. No change to the final rule is necessary regarding this issue. \n\nRequest To Add Procedure \n\n\tOne commenter requests the addition of a step in the technical procedures that returns the airplane to its normal operational configuration after the required testing (Section 2.C. ("Put the Airplane Back to Its Usual Condition") of the "Thrust Reverser Sync Lock Integrity Test"). This step was not included in AD 94-01-10. Specifically, the additional step involves returning a maintenance power switch (which was configured to "Alternate" before testing) to the "Normal" position after testing. \n\n\tThe FAA agrees with the request, for the reasons stated by the commenter. Section 2.C., set forth in paragraph (e) of this final rule, has been revised accordingly to add new step (5). The FAA has determined that this minor, axiomatic change does not expand the scope of the proposed AD. \n\nRequest To Broaden Terminating Action \n\n\tOne commenter requests that the proposed AD be revised to provide for terminating action for all actions of the AD. The commenter suggests limiting the applicability of paragraphs (a), (b), and (d) of the proposed AD to airplanes having line numbers prior to 442 (associated design changes were incorporated in production beginning with line number 442) and revising paragraphs (c) and (e) of the proposed AD to require operators to include the inspection requirements as part of their maintenance plan in the form of certification maintenance requirements (CMRs). \n\n\tThe FAA concurs with the request to revise the applicability of (a), (b), and (d). Those paragraphs have been revised accordingly. \n\n\tHowever, as explained in the proposed AD, the FAA has approved CMRs as alternative methods of compliance (AMOCs) with the inspection requirements of paragraphs (c) and (e) of AD 94-01-10 for Model 757-300 series airplanes. In addition, the FAA has approved the inspection requirements in the Boeing Maintenance Planning Document as an AMOC for the inspections required by the AD for Model 757-200 series airplanes. The intent of CMRs is not to terminate inspection requirements in ADs but to define specific repetitive inspections or component replacements for equipment, systems, and installations as a result of safety analyses approved by the FAA before an airplane type certificate is issued. Therefore, the FAA does not concur with this request to terminate the actions of paragraphs (c) and (e) of this AD. No change to the final rule is necessary in this regard. \n\nChanges to 14 CFR Part 39/Effect on the AD \n\n\tOn July 10, 2002, the FAA issued a new version of 14 CFR part 39 (67 FR 47997, July 22, 2002), which governs the FAA's airworthiness directives system. The regulation now includes material that relates to altered products, special flight permits, and alternative methods of compliance. However, for clarity and consistency in this final rule, we have retained the language of the NPRM regarding that material. \n\nConclusion \n\n\tAfter careful review of the available data, including the comments noted above, the FAA has determined that air safety and the public interest require the adoption of the rule with the changes previously described. The FAA has determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD. \n\nCost Impact \n\n\tSince this AD merely removes airplanes from the applicability of the existing AD, it adds no additional costs, and requires no additional work to be performed by affected operators. The current costs associated with this amendment are reiterated below for the convenience of affected operators: \n\n\tThe FAA estimates that 270 airplanes of U.S. registry will be affected by this AD. \n\n\tIt takes approximately 624 work hours per airplane to accomplish the modification required by AD 94-01-10, at an average labor rate of $60 per work hour. Required parts will be supplied by the manufacturer at no cost to operators. Based on these figures, the cost impact of the modification is estimated to be $37,440 per airplane.It takes approximately 1 work hour per airplane to accomplish the functional test required by AD 94-01-10, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the tests is estimated to be $60 per airplane, per test. \n\n\tThe cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions. \n\nRegulatory Impact \n\n\tThe regulations adopted herein will not have a substantial direct effect 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, it is determined that this final rule does not have federalism implications under Executive Order 13132. \n\n\tFor the reasons discussed above, I certify that this action (1) is not a "significant regulatory action" under Executive Order 12866; (2) is not a "significant rule" under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it 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\nAccordingly, 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\nPART 39--AIRWORTHINESS DIRECTIVES \n\n1. The authority citation for part 39 continues to read as follows: \n\n\tAuthority: 49 U.S.C. 106(g), 40113, 44701. \n\n§ 39.13 (Amended) \n\n2. Section 39.13 is amended by removing amendment 39-8792 (59 FR 4558, February 1, 1994), and by adding a new airworthiness directive (AD), amendment 39-13247, to read as follows: