Incident Overview
On 1 February 2020, a Sport Star RTC aircraft, registration SP-AZI, departed from Warsaw Babice Airport (EPBC). Shortly after takeoff, the pilot observed smoke spreading inside the cockpit. The smoke was identified as exhaust fumes. The pilot informed the airport information service (Info EPBC) and requested landing on runway 10. During a left turn, the pilot lowered the nose, reduced engine power, and opened the cabin windows, which stopped the smoke from entering. The aircraft landed safely on runway 10 and taxied to the hangar.
Examination Findings
A post-flight inspection revealed that the exhaust pipe tip (behind the muffler) had separated along a circumferential weld. The detached tip was later found on the runway. It was determined that the aircraft had undergone a manufacturer-recommended service bulletin (RTC – 051b) which replaced the flexible exhaust pipes with more rigid pipes featuring ball joints. At the time of the incident, the aircraft had accumulated 6 flight hours since the bulletin was performed.
Cause and Contributing Factor
The cause of the incident was the breakage of the exhaust pipe tip along a circumferential weld. A contributing factor may have been the replacement of flexible exhaust pipes with more rigid pipes with ball joints.
Safety Recommendations
No safety recommendations were formulated by the investigating body.