AD 97-07-12

This amendment supersedes an existing airworthiness directive (AD) that is applicable to certain McDonnell Douglas Model MD-11 and DC-10 series airplanes, and KC-10A (military) airplanes. That AD currently requires functional testing to verify proper installation of the electrical connectors to the engine generator and fire bell shutoff switches, and correction of the installation, if necessary. This amendment requires installation of a modification that terminates the requirement to perform repetitive functional tests. This amendment is prompted by the development of a modification that minimizes the possibility of improperly connecting (crossing) the electrical connectors to the fire extinguishing handles. The actions specified by this amendment are intended to prevent the wrong engine-driven generator from being shut down unnecessarily in the event of an engine fire warning.

Final rule.

97-07-12 MCDONNELL DOUGLAS: Amendment 39-9986. Docket 95-NM-234-AD. Supersedes AD 93-25-09 R1, Amendment 39-9070. \n\n\tApplicability: Model MD-11 series airplanes as listed in McDonnell Douglas MD-11 Alert Service Bulletin A26-16, dated November 22, 1993; and Model DC-10 series airplanes and KC-10A (military) airplanes as listed in McDonnell Douglas DC-10/KC-10A Alert Service Bulletin A26-46, dated December 6, 1993; 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 otherwise 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 (f) 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 the wrong engine-driven generator from being shut down unnecessarily in the event of an engine fire warning, accomplish the following: \n\n\t(a)\tAs of January 7, 1994 (the effective date of AD 93-25-09, amendment 39-8775), prior to further flight following any maintenance performed on the fire extinguishing handle system, perform a functional test to verify proper installation of the electrical connectors to the engine generator and fire bell shutoff switches in accordance with the Accomplishment Instructions of McDonnell Douglas MD-11 Alert Service Bulletin A26-16, dated November 22, 1993 (for Model MD-11 series airplanes); or McDonnell Douglas DC-10/KC-10A Alert Service Bulletin A26-46, dated December 6, 1993 (for Model DC-10 series airplanes, and KC-10A (military) airplanes); as applicable. \n\n\t(b)\tIf the electrical connectors are found to be properly installed, repeat the functional test thereafter prior to further flight following any maintenance performed on the fire extinguishing handle system, until the requirements of paragraph (d) of this AD are accomplished. \n\n\t(c)\tIf the electrical connectors are found to be improperly installed, prior to further flight, correct the wiring installation and repeat the functional test, in accordance with the Accomplishment Instructions of McDonnell Douglas MD-11 Alert Service Bulletin A26-16, dated November 22, 1993 (for Model MD-11 series airplanes); or McDonnell Douglas DC-10/KC-10A Alert Service Bulletin A26-46, dated December 6, 1993 (for Model DC-10 series airplanes, and KC- 10A (military) airplanes); as applicable. Thereafter, repeat the functional test prior to further flight following any maintenance performed on the fireextinguishing handle system, until the requirements of paragraph (d) of this AD are accomplished. \n\n\t(d)\tExcept as provided by paragraph (e) of this AD: Within 24 months after the effective date of this AD, install tethers on the engine generator and fire bell shutoff system and firex bottle electrical connectors, in accordance with McDonnell Douglas Service Bulletin MD11-26-018, dated August 24, 1995 (for Model MD-11 series airplanes); or McDonnell Douglas Service Bulletin DC10-26-047, Revision 1, dated August 22, 1996 (for Model DC-10 series airplanes and KC-10A (military) airplanes); as applicable. Accomplishment of this installation constitutes terminating action for the functional tests required by this AD. \n\n\t(e)\tFor those airplanes on which a functional test has been accomplished in accordance with either AD 93-25-09 R1, amendment 39-9070; or paragraph (a), (b), or (c) of this AD: The functional test specified in the "Test" procedures in paragraph 3.B. of the Accomplishment Instructions of McDonnell Douglas Service Bulletin MD11-26-018, dated August 24, 1995 (for Model MD-11 series airplanes); or McDonnell Douglas Service Bulletin DC10-26-047, Revision 1, dated August 22, 1996 (for Model DC-10 series airplanes and KC-10A (military) airplanes) need not be performed. \n\n\t(f)\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, Los Angeles 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, Los Angeles 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 Los Angeles ACO. \n\n\t(g)\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(h)\tThe functional tests shall be done in accordance with McDonnell Douglas MD-11 Alert Service Bulletin A26-16, dated November 22, 1993 (for Model MD-11 series airplanes); or McDonnell Douglas DC-10/KC-10A Alert Service Bulletin A26-46, dated December 6, 1993 (for Model DC-10 series airplanes, and KC-10A (military) airplanes); as applicable. This incorporation by reference was approved previously by the Director of the Federal Register, in accordance with 5 U.S.C. 552(a) and 1 CFR part 51, as of November 29, 1994 (59 FR 56383, November 14, 1994). The installation shall be done in accordance with McDonnell Douglas Service Bulletin MD11-26-018, dated August 24, 1995 (for Model MD-11 series airplanes); or McDonnell Douglas Service Bulletin DC10-26-047, Revision 1, dated August 22, 1996 (for Model DC-10 series airplanes and KC-10A (military) airplanes);as applicable. 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 McDonnell Douglas Corporation, 3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Technical Publications Business Administration, Department C1-L51 (2-60). Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Transport Airplane Directorate, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. \n\n\t(i)\tThis amendment becomes effective on May 13, 1997.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding AD 93-25-09 R1, amendment 39-9070 (59 FR 56383, November 14, 1994), which is applicable to certain McDonnell Douglas Model MD-11 and DC-10 series airplanes, and KC-10A (military) airplanes, was published in the Federal Register as a supplemental notice of proposed rulemaking (NPRM) on November 12, 1996 (61 FR 58012). The existing AD currently requires functional testing to verify proper installation of the electrical connectors to the engine generator and fire bell shutoff switches, and correction of the installation, if necessary. The supplemental NPRM proposed to require the installation of a modification that would terminate the requirement to perform repetitive functional tests. \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 forthe Proposal \n\n\tSeveral commenters support the proposed AD. \n\nRequest to Extend Compliance Time \n\n\tOne commenter requests that the compliance time for installation of the modification be extended from the proposed 24 months to 36 months. This commenter, a U.S. operator of affected airplanes, requests this extension so that the modification can be installed during one of this operator's regularly scheduled maintenance intervals. Adoption of the proposed compliance time of 24 months would require this operator to schedule special times for the accomplishment of the modification, at additional expense and downtime. \n\n\tThe FAA does not concur with the commenter's request to extend the compliance time. The operator provided no technical justification for revising this interval as requested. Further, in developing an appropriate compliance time for this action, the FAA considered the safety implications, parts availability, and normal maintenance schedules for timely accomplishment of the modification. In consideration of these items, the FAA has determined that 24 months represents an appropriate interval of time allowable in which the modifications can be accomplished during scheduled maintenance intervals for the majority of affected operators, and an acceptable level of safety can be maintained. However, paragraph (f) of the final rule does provide affected operators the opportunity to apply for an adjustment of the compliance time if sufficient data are presented to justify such an adjustment. \n\nRequest to Delete System Functional Test Prior to Modification \n\n\tOne commenter objects to the need to verify the extinguishing system's integrity by accomplishing engine run checks immediately prior to the installation of the terminating modification. This check procedure is specified in the referenced McDonnell Douglas Service Bulletin DC10-26-047 (both the original issue and Revision 1) as the first step to be performed on unmodified airplanes prior to installing the tethers on the engine generator and fire bell shutoff switches. This commenter maintains that the integrity of the system has already been established if the operator has been accomplishing the repetitive checks after any system maintenance, as is currently required by AD 93-25-09 R1. The commenter considers that the need to reconfirm the system's integrity is not justified. \n\n\tThe FAA concurs. The FAA has determined that as long as a functional test has been accomplished in accordance with AD 93-25-09 R1, or in accordance with paragraph (a), (b), or (c) of this final rule, there is no need to perform the additional test of the system just prior to installing the modification. A new paragraph (e) has been added to this final rule to indicate this. \n\nRequest to Rely on Maintenance Actions to Correct Unsafe Condition \n\n\tOne commenter has no technical objection to the proposal, but suggests that current maintenance practices are sufficient to identify a discrepantconnection. The commenter points out that maintenance tasks are now in place in the revised maintenance manual that will enable a cross connection condition to be readily identified. \n\n\tThe FAA does not concur. Service experience has demonstrated that maintenance alone cannot be relied upon to correct what has been determined to be a design deficiency. Reliance on maintenance to correct for a design deficiency increases the risk of introducing maintenance error and defeats the purpose of what it was meant to serve. Moreover, the installation of the modification required by this AD (at a one-time per-airplane cost of only $180 to $210 per airplane) will eliminate the need to rely on numerous long term and costly maintenance tasks. \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 change previously described. The FAA has determined that this change will neither increase the economic burden on any operator nor increase the scope of the AD. \n\nCost Impact \n\n\tThere are approximately 100 Model MD-11 airplanes, and 426 Model DC-10 series and KC-10A (military) airplanes, of the affected design in the worldwide fleet. The FAA estimates that 30 Model MD-11 airplanes, and 239 Model DC-10 series and KC-10A (military) airplanes of U.S. registry will be affected by this proposed AD. \n\n\tFor U.S.-registered Model MD-11 airplanes: The checks that are currently required by AD 93-25-09 R1 (and retained by this new AD action) take approximately 0.5 work hour per airplane to accomplish, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the actions currently required on U.S. operators of Model MD-11 airplanes is estimated to be $900, or $30 per airplane, per check. \n\n\tThe terminating modification that is required by this AD action will take approximately 3 work hours per airplaneto accomplish, at an average labor rate of $60 per work hour. The cost of required parts is expected to be negligible. Based on these figures, the cost impact of the modification requirements of this AD on U.S. operators of Model MD-11 airplanes is estimated to be $3,240, or $180 per airplane. \n\n\tFor U.S.-registered Model DC-10 series and KC-10A (military) airplanes: The checks that are currently required by AD 93-25-09 R1 (and retained by this new AD action) take approximately 0.5 work hour per airplane to accomplish, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the actions currently required on U.S. operators of these models of airplanes is estimated to be $7,170, or $30 per airplane, per check. \n\n\tThe terminating modification that is required by this AD action will take an average of 3.5 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. The cost of required parts is expected to be negligible.Based on these figures, the cost impact of the modification requirements of this AD on U.S. operators of these models of airplanes is estimated to be $50,190, or $210 per airplane. \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. \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\tFor the reasons discussed above, I certify that this action (1) is not a "significant regulatoryaction" 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\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\nPART 39 - AIRWORTHINESS DIRECTIVES \n\t1. The authority citation for part 39 continues to read as follows: \n\nAuthority: 49 U.S.C. 106(g), 40113, 44701. \n\n§ 39.13 - (Amended) \n\n\t2. Section 39.13 is amended by removing amendment 39-9070 (59 FR 56383, November 14, 1994), and by adding a new airworthiness directive (AD), amendment 39-9986, to read as follows: