What happened
During the takeoff roll, air traffic control advised the pilot that the aircraft was trailing smoke. The pilot disregarded this report, believing the smoke was a normal condition based on previous experiences, and continued the takeoff sequence.
Shortly after liftoff, the aircraft experienced a loss of thrust from the right engine. Although an attempt was made to return to the airport, the maneuver was unsuccessful. The pilot subsequently executed a forced landing into a vacant lot. There were no reported injuries.
The investigation
The investigation determined that the loss of thrust was caused by the failure of the right unfeathering accumulator hose. This failure was due to chaffing, which occurred because the hose had been misrouted during engine installation.
Additionally, the smoke initially observed by the pilot was traced to cracks in the right exhaust system. These cracks originated from previous weld repairs performed during the engine installation process. Maintenance personnel had failed to identify either the misrouted hose or the cracks in the exhaust system.