AD 93-08-18

93-08-18 PRATT & WHITNEY: Amendment 39-8566. Docket 92-ANE-16. Supersedes AD 91-05-20, Amendment 39-6919. Applicability: Pratt & Whitney Model PW4152, PW4156, and PW4158 model turbofan engines equipped with electronic engine control (EEC) Part Numbers 50D436, 50D791, 50D824, 51D037, and 51D053, installed on but not limited to Airbus A310 and Airbus A300 series aircraft. Compliance: Required within 30 days after the effective date of this airworthiness directive (AD), unless accomplished previously. To prevent a high pressure compressor failure that can be caused by excessive blade tip to airseal interference, which can result in total loss of engine thrust, accomplish the following: (a) The ENGINE ANTI ICE must be switched to "ON" prior to takeoff and must be in the "ON" position for any flight operation below 15,000 feet. (b) Install placards in the cockpit of Airbus A310-300 and A300-600 aircraft, just above the Captain and the First Officer Primary Flight Displays, indicating the following: "BEFORE TAKE OFF, SET ENG. ANTI ICE ON. KEEP ENG. ANTI ICE ON FOR ANY OPERATION BELOW 15,000 FT." NOTE: Further information on the placards may be obtained from Airbus Industrie Service Information Letter 72-001, Revision 1, dated September 18, 1990. (c) 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, Engine Certification Office. The request should be forwarded through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Engine Certification Office. NOTE: Information concerning the existence of approved alternative methods of compliance with this airworthiness directive, if any, may be obtained from the Engine Certification Office. (d) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate the airplane to a location where the requirements of this AD can be accomplished. (e) This amendment becomes effective on July 6, 1993.