SAIB ACE-96-11 —

No. ACE-96-11 December 10, 1996

Published by: FAA, AFS-613, P.O. Box 26460, Oklahoma City, OK 73125 This is issued for informational purposes only and any recommendation for corrective action is not mandatory.

INTRODUCTION: The purpose of this Special Airworthiness Information Bulletin is to provide owners/operators with information pertaining to Airworthiness Directive (AD) 96-12-06. The information contained in this bulletin provides additional information relative to the identification of cylinders and the applicability of the AD.

BACKGROUND: AD 96-12-06 allows the timing of Teledyne Continental Motors (TCM) and Rolls-Royce, plc model O-200 series engines to be set at 28° Before Top Center (BTC) when improved cylinders, P/N 641917 or higher P/N, with strengthened heads are installed. This AD supersedes AD 77-13- 03 which mandated 24° BTC engine timing because of possible cylinder cracking and subsequent loss of engine power with early part number cylinders. TCM revised Mandatory Service Bulletin (MSB) MSB94-8 which AD 96-12-06 references; the revised MSB, MSB94-8A dated 10/9/96, provides additional means to determine if the improved cylinders are installed. This is the only change to the revised service bulletin relative to the O-200 series engines. The portions of TCM MSB, MSB94-8A dated 10/9/96, which refer to the O-200 series engines have been approved as an alternate means of compliance for AD 96-12-06. The improved cylinders should have the P/N stamped on the cylinder barrel flange while the absence of a P/N on the flange usually indicates a cylinder with P/N lower than 641917 i.e. P/Ns lower than 641917 must retain the 24° BTC timing. The SB also has two figures showing the cylinder fin configuration which delineates between the old and improved cylinders. This visual aid can be used to distinguish between the old and improved cylinders. Some questions have arisen about the applicability of the AD; the AD applies only to TCM and Rolls-Royce, plc cylinders. It does not apply to any other manufacturer’s cylinder.

RECOMMENDATION: The information contained in this bulletin is being provided in response to inquiries received from owners/operators and the revision to the MSB. It was believed that owners/operators who had not contacted the FAA and/or TCM may benefit from this knowledge.

FOR FURTHER INFORMATION CONTACT: Jerry Robinette, Aerospace Engineer, FAA, Atlanta Aircraft Certification Office, Campus Building, Suite 2-160, 1701 Columbia Avenue, College Park, Georgia 30337-2748; telephone (404) 305-7371; facsimile (404) 305-7348.