AD 2002-23-18

This amendment supersedes an existing airworthiness directive (AD), applicable to certain McDonnell Douglas Model MD-11 series airplanes equipped with certain Collins LRA-900 radio altimeters, that currently requires a revision to the Airplane Flight Manual to prohibit autopilot coupled autoland operations in certain conditions; or, for certain airplanes, replacement of certain Collins LRA-900 radio altimeters with Collins LRA-700 radio altimeters. This amendment also requires a one-time inspection to determine whether a Collins LRA-900 radio altimeter receiver/transmitter with a certain part number is installed, and modification of such a radio altimeter. This amendment is prompted by reports indicating that a fault in Collins LRA-900 radio altimeters having a certain part number could result in an incorrect and unbounded output of radio altitude to other airplanes. The actions specified by this AD are intended to prevent an undetected anomalous radio altitude signal that ispassed along to the flare control law of the flight control computer, which could cause the airplane to flare too high or too low during landing, and consequently result in a hard landing. This action is intended to address the identified unsafe condition.

Final rule.

2002-23-18 Boeing: Amendment 39-12962. Docket 2000-NM-406-AD. Supersedes AD 98-24-51, Amendment 39-10929. \n\n\tApplicability: Model MD-11 and -11F airplanes equipped with certain Rockwell Collins LRA-900 radio altimeters; 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 (d)(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 an undetected anomalous radio altitude signal that is passed along to the flare control law of the flight control computer, which could cause the airplane to flare too high or too low during landing, and consequently result in a hard landing, accomplish the following: \n\nRestatement of Certain Requirements of AD 98-24-51 \n\n\t(a) Within 24 hours after December 7, 1998 (the effective date of AD 98-24-51, amendment 39-10929): accomplish either paragraph (a)(1) or (a)(2) of this AD. \n\n\t(1) Revise the Limitations Section of the FAA-approved Airplane Flight Manual to include the following statement: "Autopilot coupled autoland operations below 100 feet above ground level (AGL) are prohibited." \n\n\t(2) For airplanes on which the LRA-700 radio altimeter installation has been approved in accordance with Type Certificate or Supplemental Type Certificate procedures: Replace both Collins LRA-900 radio altimetershaving part number (P/N) 822-0334-220, with Collins LRA-700 radio altimeters having P/N 622-4542-221. \n\nNew Requirements of This AD \n\n\t(b) Within 90 days after the effective date of this AD: Perform a general visual inspection to determine the P/N of the radio altimeter receiver/transmitters, in accordance with McDonnell Douglas Service Bulletin MD11-34-091, dated August 19, 1999. \n\n\tNote 2: For the purposes of this AD, a general visual inspection is defined as: "A visual examination of an interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. This level of inspection is made from within touching distance unless otherwise specified. A mirror may be necessary to enhance visual access to all exposed surfaces in the inspection area. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or droplight and may require removal or opening of access panels or doors. Stands, ladders, or platforms may be required to gain proximity to the area being checked." \n\n\t(1) If the airplane is equipped with Collins LRA-900 radio altimeter receiver/transmitters having P/N 822-0334-220: Prior to further flight, modify the radio altimeter receiver/transmitter in accordance with McDonnell Douglas Service Bulletin MD11-34-091, dated August 19, 1999. \n\n\t(2) If the airplane is not equipped with Collins LRA-900 radio altimeter receiver/transmitters having P/N 822-0334-220: No further action is required by this paragraph. \n\n\tNote 3: Upon completion of the actions required by paragraph (b) of this AD, the revised limitations in the AFM, as required by paragraph (a)(1) of this AD, may be removed. \n\n\tNote 4: McDonnell Douglas Service Bulletin MD11-34-091, dated August 19, 1999, refers to Rockwell Avionics Service Bulletin LRA- 900-34-D, Revision 1, dated May 26, 1999, as an additional source of service information. \n\n\t(c) As of the effective date of this AD, no person shall install on any airplane a Collins LRA-900 radio altimeter having P/N 822-0334-220. \n\nAlternative Methods of Compliance \n\n\t(d)(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, Los Angeles Aircraft Certification Office (ACO), FAA. 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\t(2) Alternative methods of compliance, approved previously in accordance with AD 98-24-51, amendment 39-10929, are approved as alternative methods of compliance with this AD. \n\n\tNote 5: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Los Angeles ACO. \n\nSpecial Flight Permits \n\n\t(e) 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(f) The inspection and modification shall be done in accordance with McDonnell Douglas Service Bulletin MD11-34-091, dated August 19, 1999. 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 Boeing Commercial Aircraft Group, Long Beach Division, 3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Data and Service Management, Dept. C1-L5A (D800-0024). 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, 3960 Paramount Boulevard, Lakewood, California; or at the Office of the Federal Register, 800 North Capitol Street, NW., Suite 700, Washington, DC. \n\nEffective Date \n\n\t(g) This amendment becomes effective on December 31, 2002.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding AD 98-24-51, amendment 39-10929 (63 FR 66422, December 2, 1998), which is applicable to certain McDonnell Douglas Model MD-11 series airplanes equipped with certain Collins LRA-900 radio altimeters having certain part numbers, was published in the Federal Register on May 15, 2002 (67 FR 34637). The action proposed to continue to require a revision to the Airplane Flight Manual to prohibit autopilot coupled autoland operations in certain conditions; or, for certain airplanes, replacement of certain Collins LRA-900 radio altimeters with Collins LRA-700 radio altimeters. The action also proposed to require a one-time inspection to determine whether a Collins LRA-900 radio altimeter receiver/transmitter with a certain part number is installed, and modification of such a radio altimeter. \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 single comment received. \n\nRequest To Change Applicability \n\n\tThe commenter suggests that the applicability in the proposed AD be changed from "McDonnell Douglas Model MD-11 and -11F Airplanes Equipped with Collins LRA-900 Radio Altimeters," to "McDonnell Douglas Model MD-11 and -11F Airplanes Equipped with Collins LRA-900, Part Number (P/N) 822-0334-220, Radio Altimeters." The commenter states that this would prevent operators of MD-11 airplanes with Collins radio altimeters having other P/Ns from performing an unnecessary inspection to comply with the proposed AD. \n\n\tThe FAA acknowledges, but does not agree with, the commenter's suggestion. The inspection to determine if airplanes have the radio altimeter with the P/N specified above is required by paragraph (b) of this AD, and the affected P/N is specified in paragraph (b)(1) of this AD. Operators can ascertain what the affected P/N is, and if the radio altimeters do not have the affected P/N, no further action is required by this AD. Therefore, no change to the applicability in this final rule is necessary. \n\nExplanation of Change Made to Proposed AD \n\n\tThe FAA has clarified the inspection requirement contained in the proposed AD. Whereas the proposed AD specified a visual inspection, the FAA has revised this final rule to clarify that its intent is to require a general visual inspection. Additionally, a note has been added to the final rule to define that inspection. \n\nConclusion \n\n\tAfter careful review of the available data, including the comment 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 195 Model MD-11 and -11F airplanes of the affected designin the worldwide fleet. The FAA estimates that 64 airplanes of U.S. registry will be affected by this AD. \n\n\tThe actions that are currently required by AD 98-24-51 take approximately 1 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 currently required actions on U.S. operators is estimated to be $3,840, or $60 per airplane. \n\n\tThe new actions that are required in this AD will take approximately 1 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 new requirements of this AD on U.S. operators is estimated to be $3,840, or $60 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. The cost impact figures discussed in ADrulemaking 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\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\n\tAuthority: 49 U.S.C. 106(g), 40113, 44701. \n\n§ 39.13 (Amended) \n\n\t2. Section 39.13 is amended by removing amendment 39-10929 (63 FR 66422, December 2, 1998), and by adding a new airworthiness directive (AD), amendment 39-12962, to read as follows: