89-23-10 BOEING: Amendment 39-6375. Docket No. 88-NM-212-AD. \n\n\tApplicability: Model 737-300 and -400 series airplanes, certificated in any category. \n\n\tCompliance: Required within 10 days after the effective date of this AD, unless previously accomplished. \n\n\tTo reduce the risk of jeopardizing continued safe flight and landing due to engine ice ingestion, accomplish the following: \n\n\tA.\tIncorporate Boeing Operations Manual Bulletin 737-300-89-1 or 737-400-89-1, both dated February 14, 1989, as appropriate, into the Airplane Operations Manual. \n\n\tB.\tAn 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, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region. \n\n\tNOTE: The request should be forwarded through an FAA Principal Operations Inspector (POI), who will either concur or comment and then send it to the Manager, Seattle Aircraft Certification Office. \n\n\tAll persons affected by this directive who have not already received the appropriate service documents from the manufacturer may obtain copies upon request to Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124. These documents may be examined at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 17900 Pacific Highway South, Seattle, Washington, or Seattle Aircraft Certification Office, 9010 East Marginal Way South, Seattle, Washington. \n\n\tThis amendment (39-6375, AD 89-23-10) becomes effective on December 4, 1989.