What happened
During the en route climb, the left engine of the aircraft produced a loud noise and lost power. The pilot responded by retarding the throttle and initiating a turn to return to the airport. Upon noticing that the engine nacelle was on fire, the pilot shut off the fuel supply, which appeared to extinguish the flames.
The pilot then proceeded to retard the mixture and propeller controls; however, this action did not follow the proper sequence outlined in the airplane owner's manual. Additionally, the propeller failed to feather. Despite applying full power to the right engine and maintaining the best single-engine rate of climb speed, the aircraft continued to descend at a rate of 200 to 250 feet per minute.
The pilot performed a forced wheels-down landing in an open field. During the maneuver, the aircraft struck a terrace, causing the landing gear to collapse. The occupants were not injured.
The investigation
A post-accident inspection of the engine revealed a loose fuel injector supply line. Investigators also found heat damage and a 1-1/2 inch brown stain on the clamp that attaches the tailpipe to the exhaust side of the turbocharger. Records indicated that engine maintenance, which involved the removal and reattachment of fuel lines, had been performed on the aircraft just prior to the flight.