AD 95-11-13

This amendment adopts a new airworthiness directive (AD) that is applicable to certain McDonnell Douglas Model MD-11 series airplanes. This action requires a visual inspection to detect cracks or discrepancies in the aft mount beam assembly of the engines; and replacement of the cracked or discrepant aft mount beam assembly with a new assembly, or a previously inspected and re-identified assembly. This amendment is prompted by reports of cracking in a certain aft mount beam assembly on Airbus Model A310 series airplanes. The actions specified in this AD are intended to prevent cracks in the aft mount beam assembly of the engines, which could result in loss of the capability of the aft mount beam assembly to support engine loads, and possible separation of the engine from the airplane.

Final rule; request for comments.

95-11-13 MCDONNELL DOUGLAS: Amendment 39-9246. Docket 95-NM-96-AD.\n\n\tApplicability: Model MD-11 series airplanes, equipped with Pratt & Whitney Model PW4460 and PW4462 engines; as listed in McDonnell Douglas Alert Service Bulletin MD11-71A073, Revision 1, dated May 16, 1995; 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 use the authority provided in paragraph (d) to request approval from the FAA. This approval may address either no action, if the current configuration eliminates the unsafe condition; or different actions necessary to address the unsafe condition described in this AD. Such a request should include an assessment ofthe effect of the changed configuration on the unsafe condition addressed by this AD. In no case does the presence of any modification, alteration, or repair remove any airplane from the applicability of this AD.\n\n\tCompliance: Required as indicated, unless accomplished previously.\n\n\tTo prevent loss of the capability of the aft mount beam assembly to support engine loads, and possible separation of the engine from the airplane, accomplish the following:\n\n\t(a)\tWithin 60 days after the effective date of this AD, perform a visual inspection to detect cracks or discrepancies in the aft mount beam assembly, part number (P/N) 221-0261-501, of engine numbers 1, 2, and 3, in accordance with McDonnell Douglas Alert Service Bulletin MD11-71A073, Revision 1, dated May 16, 1995.\n\n\t\t(1)\tIf no cracks or discrepancies are detected, no further action is required by this AD.\n\n\t\t(2)\tIf any crack or discrepancy is detected, prior to further flight, replace the cracked or discrepant aft mountbeam assembly with a new assembly having P/N 221-0261-503, or an assembly having P/N 221-0261-501 that has been previously inspected and re-identified, in accordance with paragraph 3.B., Phase 2, of the Accomplishment Instructions of the alert service bulletin. Replacement shall be accomplished in accordance with the procedures specified in the alert service bulletin.\n\n\t(b)\tWithin 10 days after accomplishing the inspection required by this AD, report inspection results, positive or negative, to the Manager, Los Angeles Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate, 3960 Paramount Boulevard, Lakewood, California 90712; fax (310) 627-5210. Information collection requirements contained in this regulation have been approved by the Office of Management and Budget (OMB) under the provisions of the Paperwork Reduction Act of 1980 (44 U.S.C. 3501 et seq.) and have been assigned OMB Control Number 2120-0056.\n\n\t(c)\tAs of the effective date of this AD, no person shall install an aft mount beam assembly, P/N 221-0261-501, on any airplane, unless it has been previously inspected and re-identified in accordance with the paragraph 3.B., Phase 2, of the Accomplishment Instructions of McDonnell Douglas Alert Service Bulletin MD11-71A073, Revision 1, dated May 16, 1995.\n\n\t(d)\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 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(e)\tSpecial flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and21.199) to operate the airplane to a location where the requirements of this AD can be accomplished.\n\n\t(f)\tThe inspection, replacement, and re-identification shall be done in accordance with McDonnell Douglas Alert Service Bulletin MD11-71A073, Revision 1, dated May 16, 1995. 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, Los Angeles Aircraft Certification Office, Transport Airplane Directorate, 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(g)\tThis amendment becomes effective on June 16, 1995.

The FAA has received reports of cracking in an aft mount beam assembly having part number (P/N) 221-0261-501 installed on Airbus Model A310 series airplanes. Metallurgical analysis and close examination of the cracked aft mount beam assembly has indicated this cracking is the result of physical defects, which were caused during the forging process by one supplier. Cracks in the aft mount beam assembly of the engines, if not detected and corrected in a timely manner, could result in loss of the capability of the aft mount beam assembly to support engine loads, and possible separation of the engine from the airplane.\n\n\tAft mount beam assemblies having P/N 221-0261-501 are also installed on McDonnell Douglas Model MD-11 series airplanes equipped with Pratt & Whitney PW4460 and PW4462 engines. The FAA has determined that these airplanes are also subject to the addressed unsafe condition.\n\n\tThe FAA may consider similar rulemaking action that is applicableto Airbus Model A310 series airplanes on which the suspect mount beam assembly also may be installed.\n\n\tThe FAA has reviewed and approved McDonnell Douglas Alert Service Bulletin MD11-71A073, Revision 1, dated May 16, 1995, which describes procedures for a one-time visual inspection to detect cracks or discrepancies in the aft mount beam assembly, P/N 221-0261-501, of engine numbers 1, 2, and 3. This alert service bulletin also describes procedures for replacement of the cracked or discrepant aft mount beam assembly with a new assembly having P/N 221-0261-503, or a previously inspected and re-identified assembly having P/N 221-0261-501.\n\n\tSince an unsafe condition has been identified that is likely to exist or develop on certain other McDonnell Douglas Model MD-11 series airplanes of the same type design, this AD is being issued to prevent loss of the capability of the aft mount beam assembly to support engine loads, and possible separation of the engine from the airplane. This AD requires a one-time visual inspection to detect cracks or discrepancies in the aft mount beam assembly of the engines; and replacement of the cracked or discrepant aft mount beam assembly with a certain new assembly, or a certain previously inspected and re-identified assembly. The actions are required to be accomplished in accordance with the alert service bulletin described previously.\n\n\tThis AD also requires that operators report results of inspection findings, positive or negative, to the FAA.\n\n\tThe FAA is considering further rulemaking action to require fluorescent penetrant and eddy current inspections of the aft mount beam assembly, P/N 221-0261-501, of the engines within 4,000 flight cycles after accomplishing the visual inspection required by this AD. However, the proposed compliance time for the one-time visual inspection is sufficiently long so that notice and time for public comment would not be impracticable.\n\n\tAs a result of recent communications with the Air Transport Association (ATA) of America, the FAA has learned that, in general, some operators may misunderstand the legal effect of AD's on airplanes that are identified in the applicability provision of the AD, but that have been altered or repaired in the area addressed by the AD. The FAA points out that all airplanes identified in the applicability provision of an AD are legally subject to the AD. If an airplane has been altered or repaired in the affected area in such a way as to affect compliance with the AD, the owner or operator is required to obtain FAA approval for an alternative method of compliance with the AD, in accordance with the paragraph of each AD that provides for such approvals. A note has been added to this final rule to clarify this long-standing requirement.\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 formaking this amendment effective in less than 30 days.\n\nComments Invited\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 following statement is made: "Comments to Docket Number 95-NM-96-AD." The postcard will be date stamped and returned to the commenter.\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\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.\n\nAdoption of the Amendment\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.\tThe authority citation for part 39 continues to read as follows:\nAuthority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 106(g); and 14 CFR 11.89.\n\n§ 39.13 - (Amended)\n\t2.\tSection 39.13 is amended by adding the following new airworthiness directive: