AD 94-22-01

This amendment supersedes an existing airworthiness directive (AD), applicable to all McDonnell Douglas Model DC-10-10, -10F, -30, and -30F series airplanes, that currently requires inspections to detect ice or snow accumulation on top of the fuselage and in the inlet of the number 2 engine, and removal of ice and snow accumulation. This amendment adds certain airplanes to the applicability of the rule and limits the inspection requirement to only a certain group of airplanes. This amendment is prompted by the development of improved fan blades on certain engines and the identification of additional airplanes that are subject to the unsafe condition. The actions specified by this AD are intended to minimize damage to the number 2 engine due to ingestion of ice and snow.

Final rule.

94-22-01 MCDONNELL DOUGLAS: Amendment 39-9050. Docket 94-NM-22-AD. Supersedes AD 75-04-11, Amendment 39-2094. \n\n\tApplicability: Model DC-10-10, -10F, -30, -30F, and -15 series airplanes, and Model KC-10A (military) airplanes, on which the number 2 engine is a General Electric Model CF6 series turbofan engine having one or more gundrilled fan blades installed, including but not limited to part numbers 9010M33 and 9137M39; certificated in any category. \n\n\tCompliance: Required as indicated, unless accomplished previously. \n\n\tTo prevent possible damage to the number 2 engine due to ingestion of ice and snow, accomplish the following: \n\n\t(a)\tAs of the effective date of this AD, prior to starting the number 2 engine on any airplane that has been parked during icing conditions (freezing rain, snow, sleet) for any period of time during which ice or snow may have accumulated on the airplane in the area of the number 2 engine, inspect to detect ice and snow accumulation on top ofthe fuselage and in the inlet of the number 2 engine. If ice or snow accumulation is found, prior to further flight, remove the ice or snow accumulation. \n\n\tNOTE 1: Guidelines for inspection and safeguarding the aircraft are contained in these documents: \n\n\t\tDouglas All Operators Letter (AOL) 10-546, dated January 11, 1974 \n\n\t\tDouglas AOL 10-673, dated August 7, 1974 \n\n\t\tDC-10 Airplane Maintenance Manual, Chapter 12-31-01 \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)\tThis amendment becomes effective on November 28, 1994.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding AD 75-04-11, amendment 39-2094, which is applicable to all McDonnell Douglas Model DC-10-10, -10F, -30, and -30F series airplanes, was published in the Federal Register on July 18, 1994 (59 FR 36375). The action proposed to supersede AD 75-04-11, which currently requires inspections to detect ice and snow accumulation on top of the fuselage and in the inlet of the number 2 engine, and removal of ice and snow. The action proposed to add Model DC-10-15 series airplanes to the applicability of the rule, and to limit the inspection requirement to only a certain group of airplanes. \n\n\tInterested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the single comment received. \n\n\tThe commenter supports the proposed rule. \n\n\tAfter careful review of the available data, including the commentnoted above, the FAA has determined that air safety and the public interest require the adoption of the rule as proposed. \n\n\tThere are approximately 379 McDonnell Douglas Model DC-10-10, -10F, -30, -30F, and -15 series airplanes and Model KC-10A (military) airplanes of the affected design in the worldwide fleet. The FAA estimates that 226 airplanes of U.S. registry will be affected by this AD. (Currently, there are no Model DC-10-15 series airplanes of U.S. registry that will be affected by this AD.) \n\n\tThe inspections that were previously required by AD 75-04-11, and retained in this AD take approximately 1 work hour per airplane to accomplish the required actions, and that the average labor rate is $55 per work hour. Based on these figures, the total cost impact of the inspection requirement on U.S. operators is estimated to be $12,430, or $55 per airplane, per inspection. This AD will only add the cost of inspections for the operators of Model KC-10A (military) airplanes.For operators of Model DC-10-10, -10F, -30, and -30F series airplanes having all solid fan blades in the number 2 engine position, the economic burden will be reduced since the previous requirement to inspect these airplanes in accordance with the existing AD will be eliminated by this AD. However, this does not relieve operators of the responsibility to comply with the requirements of sections 91.527 ("Operating in icing conditions") and 121.629 ("Operation in icing conditions"--air carriers) of the Federal Aviation Regulations (14 CFR 91.527 and 121.629). \n\n\tThe total 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\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 distributionof 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, Safety.\n\n Adoption 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.\tThe authority citation for part 39 continues to read as follows: \n\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\n\t2.\tSection 39.13 is amended by removing amendment 39-2094, and by adding a new airworthiness directive (AD), amendment 39-9050, to read as follows: