89-23-09: Landing Gear Warning System

89-23-09 EMPRESA BRASILEIRA DE AERONAUTICA, S.A. (EMBRAER): Amendment 39-6372. Docket No. 89-NM-89-AD. Applicability: Model EMB-120 series airplanes; Serial numbers 120004, 120006 through 120070, 120072 through 120080, and 120082 through 120099; certificated in any category. Compliance: Required within 180 days after the effective date of this AD, unless previously accomplished. To prevent a gear-up landing due to malfunction of the landing gear aural warning system, accomplish the following: A. Modify the landing gear aural warning system and calibrate new switches, in accordance with either EMBRAER Service Bulletin No. 120-032-0055 dated March 16, 1989, or EMBRAER Service Bulletin No. 120-032-0052, dated March 15, 1989. B. An alternate means of compliance or adjustment of the compliance time, which provides an acceptable level of safety, may be used when approved by the Manager, Atlanta Aircraft Certification Office, FAA, Central Region. NOTE: The request for an alternate means of compliance or an adjustment of the compliance time should be forwarded through an FAA Maintenance Inspector, who will either concur or comment and then send it to the Atlanta Aircraft Certification Office. C. Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base in order to comply with the requirements of this AD. All persons affected by this directive who have not already received the appropriate service documents from the manufacturer may obtain copies upon request to EMBRAER, 276 S.W. 34th Street, Fort Lauderdale, Florida 33315. These documents may be examined at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 17900 Pacific Highway South, Seattle, Washington, or the FAA, Central Region, Atlanta Aircraft Certification Office, 1669 Phoenix Parkway, Suite 210C, Atlanta, Georgia. This amendment (39-6372, AD 89-23-09) becomes effective on December 1, 1989.