SAIB NE-13-04

FAA Aviation Safety

SPECIAL AIRWORTHINESS

INFORMATION BULLETIN SAIB: NE-13-04 SUBJ: Continental Motors, Inc. (CMI) Connecting Rod Piston Pin Bushing Inspection Date: October 31, 2012 This is information only. Recommendations aren’t mandatory.

Introduction

This Special Airworthiness Information Bulletin (SAIB) alerts registered owners, operators, and certified repair facilities of all airplanes equipped with Continental Motors, Inc. (CMI) series engines (all models) of the service instructions to inspect the connecting rod piston pin bushing installation at each cylinder removal or any time piston pin bushing material is identified during routine maintenance procedures.

At this time, the airworthiness concern is not an unsafe condition that would warrant airworthiness directive (AD) action under Title 14 of the Code of Federal Regulations (14 CFR) part 39.

Background

The issuance of this SAIB is prompted by reports the FAA received from the field of piston pin bushing material being found in the engine sump and oil filter on certain CMI series engines. Piston pin bushings are manufactured from steel-back bronze and are curved on a radius of 0.062". The affected engine models as well as instructions for inspection of the connecting rod piston pin bushing installation are presented in CMI Service Bulletin SB07-1, dated March 19, 2007. Potential factors contributing to bushing failure are the connecting rod pin bore chamfer and positioning of the piston pin bushing split line within the required arc of the connecting rod center line. The connecting rod via a design change was modified to incorporate a less generous chamfer at the connecting rod pin bore.

Recommendations

At each cylinder removal or if piston pin bushing material is recovered from an engine during routine maintenance, we recommend that you remove all the cylinders, pistons, and piston pins to facilitate access for inspection of the connecting rod piston pin bushings. In addition, we recommend that you inspect the piston pin bushing for condition each time a cylinder is removed from the engine for any reason.

For Further Information Contact

Anthony Holton, Aerospace Engineer, Atlanta Aircraft Certification Office, Small Airplane Directorate, 1701 Columbia Ave., College Park, GA 30337; phone: (404) 474-5567; fax: (404) 474- 5806; e-mail: Anthony.holton@faa.gov.

For Related Service Information Contact

Continental Motors, Inc., Factory Service, 2039 South Broad Street, Mobile, AL 36615; phone: (800) 326-0089.