Incident Description
During cruise climb, the left engine exhaust nozzle and fairing separated from the aircraft. The flight crew reported hearing a "small thud" while climbing through 15,000 feet msl. They monitored the engines and observed no anomalies, attributing the event to possible wake turbulence. The crew elected to continue to the scheduled destination. During a post-flight inspection, they discovered the left engine exhaust nozzle and fairing were missing.
Examination Findings
The left engine exhaust nozzle was located approximately 26.5 nautical miles west-southwest of the departure airport. Examination revealed that the attachment hardware was missing. The bolt holes used to install the nozzle to the engine were elongated and showed evidence of fretting.
Maintenance History
The exhaust nozzle manufacturer issued Service Bulletin CF34-NAC-78-024 on January 24, 2003, to address "exhaust nozzle bolt attachment failures." The service bulletin called for removal of existing hardware and replacement with "new, improved hardware," to be completed at the operator's earliest convenience or within a maximum of 4,000 hours. At the time of the incident, the aircraft had accumulated 3,440 hours since new. According to maintenance records, the service bulletin had not been complied with.
Operator Response
The operator immediately inspected their entire fleet of Bombardier CL-600-2B19 regional jets and found three additional aircraft with either missing or loose attachment exhaust nozzle hardware. The operator ordered replacement kits for the entire fleet and stated they would comply with Service Bulletin CF34-NAC-78-024 upon delivery of the replacement parts.