AD 99-10-14 Airworthiness Directives; Boeing Model 747-400, 757, 767, and 777 Series Airplanes Equipped With AlliedSignal RIA-35B Instrument Landing System (ILS) Receivers

Models named: 747-400, 757, 767, 777 series. Read the applicability below — it usually turns on serial or part numbers too.

Model 747-400, 757, 767, and 777 series airplanes; equipped with AlliedSignal RIA-35B Instrument Landing System (ILS) receivers, part number (P/N) 066-50006-0101, certificated in any category. Note 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 (e) 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.

Required as indicated, unless accomplished previously. To prevent erroneous localizer deviation provided by faulty ILS receivers, which could result in a landing outside the lateral boundary of the runway, accomplish the following: Restatement of the Requirements of AD 98-14-10 (a) Within 10 days after July 22, 1998 (the effective date of AD 98-14-10, amendment 39-10643), revise the Limitations Section of the FAA-approved Airplane Flight Manual (AFM) to include the following statement. This may be accomplished by inserting a copy of this AD into the AFM. ``Any Instrument Landing System (ILS) or Localizer approach with only one operative AlliedSignal ILS receiver, P/N 066-50006-0101, installed is prohibited.'' Note 2: On Model 747-400 and 777 series airplanes, the existence of only one operative ILS receiver is indicated by the Engine Indication and Crew Alerting System advisory message, ``SNGL SOURCE ILS.'' On Model 757 and 767 series airplanes, failure of an ILS receiver is indicated by an ILS flag on the display of the Electronic Flight Instrument System when approach mode is selected. (b) Within 30 days after July 22, 1998, accomplish the requirements of either paragraph (b)(1) or (b)(2) of this AD. (1) Perform a visual inspection of the 64 flight legs of the internal fault memory of all AlliedSignal RIA-35B ILS receivers, P/N 066-50006-0101, for fault codes ``Nl'' (glide slope antialias fault) or ``Nm'' (localizer antialias fault). Repeat the inspection thereafter at intervals not to exceed 64 flight cycles. If any fault code ``Nl'' or ``Nm'' is found, prior to further flight, replace the existing ILS receiver with a new or serviceable ILS receiver having the same P/N; or with an ILS receiver that has been modified to P/N 066-50006-1101 in accordance with AlliedSignal Electronic and Avionics Systems Service Bulletin M-4426 (RIA-35B-34-6), Revision 3, dated May 1998. Installation of an ILS receiver that has been modified (and the P/N converted) in accordance with the service bulletin constitutes terminating action for the inspection requirement of paragraph (b)(1) of this AD for that part. (2) Accomplish the actions required by paragraphs (b)(2)(i) and (b)(2)(ii) of this AD. (i) Revise the Limitations Section of the FAA-approved AFM to include the following statement. This may be accomplished by inserting a copy of this AD into the AFM. ``Category II and III operations are prohibited with AlliedSignal ILS receiver P/N 066-50006-0101 installed.'' (ii) Install a placard on the forward instrument panel of the cockpit in clear view of the pilots, which states: ``Category II and III operations are prohibited.'' (c) As of July 22, 1998, no person shall install on any airplane an RIA-35B ILS receiver, P/N 066-50006-0101, that has been found to be discrepant (that is, on which fault codes ``Nl'' or ``Nm'' were found during an inspection of the internal fault memory) unless the discrepancy has been corrected by modifying the ILS receiver in accordance with AlliedSignal Electronic and Avionics Systems Service Bulletin M-4426 (RIA-35B-34-6), Revision 3, dated May 1998. New Requirements of This AD (d) Within 6 months after the effective date of this AD, replace all existing RIA-35B ILS receivers, P/N 066-50006-0101, with RIA-35B ILS receivers that have been modified in accordance with AlliedSignal Electronic and Avionics Systems Service Bulletin M-4426 (RIA-35B-34-6), Revision 3, dated May 1998; and that have had their P/N's [[Page 25806]] converted to 066-50006-1101. Such replacement constitutes terminating action for the requirements of this AD. After the replacement has been accomplished, the AFM limitations required by paragraphs (a) and (b)(2)(i) of this AD may be removed from the AFM, and the placard required by (b)(2)(ii) may be removed from the cockpit. Note 3: Modification of all AlliedSignal RIA-35B ILS receivers, P/N 066-50006-0101, prior to July 22, 1998, in accordance with AlliedSignal Electronic and Avionics Systems Service Bulletin M-4426 (RIA-35B-34-6), dated December 1997; Revision 1, dated January 1998; or Revision 2, dated April 1998; is considered acceptable for compliance with the applicable action specified in this amendment. Alternative Methods of Compliance (e) 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, Seattle 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, Seattle ACO. Note 4: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Seattle ACO. Special Flight Permits (f) 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. Incorporation by Reference (g) The modification shall be done in accordance with AlliedSignal Electronic and Avionics Systems Service Bulletin M-4426 (RIA-35B-34-6), Revision 3, dated May 1998. The incorporation by reference of this document was approved previously by the Director of the Federal Register as of July 22, 1998 (63 FR 36549, July 7, 1998). Copies may be obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-2207. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. (h) This amendment becomes effective on June 17, 1999. Issued in Renton, Washington, on May 4, 1999. D.L. Riggin, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 99-11782 Filed 5-12-99; 8:45 am] BILLING CODE 4910-13-P