AD 98-09-19

This amendment adopts a new airworthiness directive (AD), applicable to certain McDonnell Douglas Model DC-9, DC-9-80, and C-9 (military) series airplanes, and Model MD-88 airplanes, that requires modification of certain non-regulating shutoff valves on the engine starter, or installation of a pressure relief valve in the pneumatic supply line to the starter air shutoff valve on engines 1 and 2. This amendment is prompted by reports of uncontained failures of engine starters during flight and maintenance, which resulted from the application of excessive pressure on the engine starter that was associated with the installation of non-regulating shutoff valves on the starter. The actions specified by this AD are intended to prevent such uncontained failures of the engine starters, which could create a fire hazard in the engine nacelle.

Final rule.

98-09-19 MCDONNELL DOUGLAS: Amendment 39-10500. Docket 96-NM-199-AD. \n\n\tApplicability: Model DC-9, DC-9-80, and C-9 (military) series airplanes and Model MD-88 airplanes, on which a converted or first production non-regulating shutoff valve having Allied Signal Aerospace part number (P/N) 979410-1-1 or 979410-2-1 has been installed on the engine starter; 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 (b) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressedby 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 application of excessive pressure on the engine starter, which could cause uncontained failure of an engine starter and, consequently, could create a fire hazard in the nacelle of the engine, accomplish the following: \n\n\t(a)\tWithin 24 months after the effective date of this AD, accomplish either paragraph (a)(1) or (a)(2) of this AD. \n\n\t\t(1)\tModify any converted or first production non-regulating shutoff valve, P/N 979410-1-1 or 979410-2-1, on the starter of engines 1 and 2 by installing a pressure regulator on the valve in accordance with Allied-Signal Aerospace Service Bulletin 979410-80-1611, dated November 27, 1995; or Allied-Signal Aerospace Service Bulletin 979410-80-1611, Revision 1, dated March 13, 1997; or McDonnell Douglas Service Bulletin DC9-80-010, dated August 22, 1997. Or \n\n\t\t(2)\tInstall a pressure relief valve in the pneumatic supply line to the starter air shutoff valve on engines 1 and 2 in accordance with McDonnell Douglas Service Bulletin DC9-80-014, dated August 22, 1997. \n\n\t(b)\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(c)\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(d)\tThe actions shall be done in accordance with McDonnell Douglas Service Bulletin DC9-80-010, dated August 22, 1997; McDonnell Douglas Service Bulletin DC9-80-014, dated August 22, 1997; Allied-Signal Aerospace Service Bulletin 979410-80-1611, dated November 27, 1995; and Allied-Signal Aerospace Service Bulletin 979410-80-1611, Revision 1, dated March 13, 1997. Allied-Signal Aerospace Service Bulletin 979410-80-1611, Revision 1, dated March 13, 1997, contains the specified effective pages: \n\n\nPage Number\nRevision Level\nShown on Page\nDate\nShown on Page\n1, 6, 7, 14, 15, 17, 18\n1\nMarch 13, 1997\n2-5, 8-13, 16\nOriginal\n November 27, 1995 \n \t\nThis 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 Allied Signal Fluid Systems, Technical Publications Department, Building 1230_V,Mail Stop 65-92, P.O. Box 22200, Tempe, Arizona 85285-2200. 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(e)\tThis amendment becomes effective on June 3, 1998.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that is applicable to certain McDonnell Douglas Model DC-9, DC-9-80, and C-9 (military) series airplanes, and Model MD-88 airplanes, was published in the Federal Register on October 23, 1996 (61 FR 54961). That action proposed to require modification of certain converted or first production non- regulating shutoff valves on the engine starter. \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 Proposal \n\n\tOne commenter supports the proposed AD. \n\nRequest to Allow Installation of Relief Valve in Lieu of Pressure Regulator \n\n\tThe Air Transport Association (ATA) of America, on behalf of several of its members, requests that the FAA require installation of a relief valve rather than a pressure regulator. One ATA member states that installation of a relief valve is considered to be a more cost efficient and expeditious method of compliance. Other ATA members state that the pressure regulator feature was removed previously from the start valve due to poor valve reliability caused by contamination. \n\n\tThe FAA concurs partially. The FAA does not agree that installation of a relief valve should be required in lieu of a pressure regulator. However, the FAA agrees that installation of a relief valve could be provided as an additional method of compliance for the requirements of this AD. \n\n\tSince the issuance of the proposed rule, the FAA has reviewed and approved McDonnell Douglas Service Bulletin DC9-80-014, dated August 22, 1997, which describes procedures for installation of a pressure relief valve in the pneumatic supply line to the starter air shutoff valve on engines 1 and 2. Installation of the pressure relief valve and applicable pipe assembly in the muscle pressure line upstream of the starter air shutoff valve will prevent uncommanded opening of the starter valve and will prevent excessive air pressure to the engine starter. The FAA has revised paragraph (a) of this final rule to include accomplishment of the actions specified in this service bulletin as an additional method of compliance for the requirements of that paragraph. \n\n\tAdditionally, the FAA has revised the wording of this final rule to specify that the requirement of paragraph (a)(1) is to modify any converted or first production non-regulating shutoff valve on the starter of engines 1 and 2 by installing a pressure regulator on the valve. \n\nRequest for Extension of Compliance Time \n\n\tSeveral commenters request that the proposed compliance time of 12 months be extended to as much as 24 months. Two commenters state that most valves must be sent to vendors for modification, which would make it difficult to accomplish the requirements of the proposal within 12 months. Another commenter indicates that an extension of the compliance time would provide an acceptable level of safety without having a negative impact on operations. \n\n\tThe FAA concurs with the commenters' requests. Paragraph (a) of this final rule has been revised to specify a compliance time of 24 months. This extension of compliance time should provide operators ample time to accomplish the required modification without compromising safety. \n\nRequest to Revise Cost Impact Information \n\n\tOne commenter indicates that the cost impact information, below, is understated. The commenter states that there are two valves per airplane, and unless Allied Signal offers a compensatory program, the estimated cost will exceed the figure provided in the proposed rule. The FAA does not concur. The cost impact information specified in this final rule was provided to the FAA by the vendor based on the best available data to date. No change to this final rule is necessary. \n\nAdditional Service InformationSince the issuance of the proposed rule, the FAA has reviewed and approved McDonnell Douglas Service Bulletin DC9-80-010, dated August 22, 1997, which describes procedures for installation of an air pressure regulator in the starter air shutoff valve, which will minimize the possibility of excessive starter air pressure that could result in a starter uncontained failure. The FAA has revised paragraph (a) of this final rule to reference this service bulletin as an additional source of service information for accomplishment of this installation. \n\n\tThe FAA also has reviewed and approved Revision 1 of Allied Signal Aerospace Service Bulletin 979410-80-1611, dated March 13, 1997. Revision 1 of the service bulletin is essentially identical to the original issue; however, Figure 1 of the service bulletin has been revised to clarify certain measurements. The FAA has included a reference to this service bulletin revision in the final rule as an additional source of service information.Conclusion \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\tThere are approximately 1,970 Model DC-9, DC-9-80, and C-9 (military) series airplanes and Model MD-88 airplanes of the affected design in the worldwide fleet. The FAA estimates that 1,100 airplanes of U.S. registry will be affected by this AD, that it will take approximately 16 work hours per airplane to accomplish the required actions, and that the average labor rate is $60 per work hour. Required parts will cost approximately $400 per airplane. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $1,496,000, or $1,360 per airplane. \n\n\tThe cost impact figure discussed above is 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 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\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\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 adding the following new airworthiness directive: