What happened
A pilot, acting as the company owner, was performing a takeoff from his base of operations at an airport in rural Alaska. The aircraft was carrying a new hire pilot and four passengers. Approximately one mile from the airport, the crew and passengers observed and smelled smoke.
The pilot immediately returned to the airport and landed the aircraft. Following the landing, the pilot requested that the new hire pilot exit the airplane to check the engine oil dipstick for security. After this inspection, the new hire pilot reentered the cockpit, and the pilot attempted a second takeoff.
Shortly after the second departure, smoke filled the cockpit and flames became visible emerging from the engine cowling. The pilot performed an emergency landing on a small island located just off the airport. The five occupants of the aircraft used water and a small fire extinguisher to extinguish the fire. All occupants were not injured.
The investigation
A postaccident inspection of the aircraft revealed fire damage near the exposed exhaust ports and a loose exhaust manifold. Investigators found the nuts used to affix the exhaust manifold to the engine had fallen into the bottom of the cowling. Records indicated that maintenance had been performed on the aircraft approximately one month prior, which required the removal of the left manifold.