What happened
During a straight-in approach to a runway at night, the aircraft collided with trees located approximately 2,37<0xA0>78 feet short of the runway. Following the collision with the trees, the airplane descended and struck the ground, coming to rest in an upright position. At the time of the accident, there was no visual approach slope indicator available to the pilot.
The investigation
Investigators examined the engine and flight controls, finding no evidence of any malfunction or failure occurring prior to the impact. An inspection of the engine assembly determined that while the alternator was physically installed on the engine, its electrical connections had not been secured. It was determined that the pilot departed on the return flight without the alternator being properly installed.
Additionally, an examination of the landing light bulb showed a broken filament, though the filament was not stretched. The landing light switch was found in the 'on' position. According to fire and rescue personnel, the battery, alternator, fuel pump, and anticollision switches were all in the 'on' position in the cockpit before being turned off.