98-24-51: AFM - Autoland System

98-24-51 MCDONNELL DOUGLAS: Amendment 39-10929. Docket 98-NM-334-AD. \n\n\tApplicability: Model MD-11 series airplanes, equipped with certain Collins LRA-900 radio altimeters, having part number 822-0334-002, 822-0334-020, or 822-0334-220; certificated in any category. \n\n\tCompliance: Required as indicated, unless accomplished previously. \n\n\tTo detect and correct 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\n\t(a)\tWithin 24 hours after the effective date of this AD, accomplish either paragraph (a)(1) or (a)(2) of this AD: \n\n\t\t(1)\tRevise the Limitations Section of the FAA-approved Airplane Flight Manual to include the following statement: \n\n"Autopilot coupled autoland operations below 100 feet above ground level (AGL) are prohibited."\n\n\t\t(2)\tFor 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 altimeters having part number 822-0334-002, 822-0334-020, or 822-0334-220, with Collins LRA-700 radio altimeters having part number 622-4542-221. \n\n\t(b)\tAs of the effective date of this AD, no person shall install on any airplane a Collins LRA-900 radio altimeter, having part number 822-0334-002, 822-0334-020, or 822-0334-220. \n\n\t(c)\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: 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(d)\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(e)\tThis amendment becomes effective on December 7, 1998, to all persons except those persons to whom it was made immediately effective by telegraphic AD T98-24-51, issued on November 19, 1998, which contained the requirements of this amendment.