What happened
The flight proceeded without incident during the en route phase, although the pilot incorrectly used the aircraft's registration number as a call sign. Upon arriving at Boston, air traffic control provided radar vectors and cleared the pilot for an Instrument Landing System approach to runway 4R, instructing him to contact the tower. The pilot established communication with the tower and reported passing over the outer marker. Shortly thereafter, the aircraft entered a left turn, after which both radio and radar contact were lost. The aircraft crashed approximately 2.5 miles southeast of the airport.
A witness near the crash site observed the aircraft descending in a westerly direction and believed it was experiencing engine problems. The witness reported that the engines appeared to smooth out and the plane began to climb, but it suddenly entered a dive before impact. During the collision, the aircraft struck a residence and a parked automobile. The impact and subsequent fire destroyed three houses and ten cars, while other nearby homes sustained damage from the fire.
The investigation
Investigators examined the wreckage and found no evidence of pre-impact part failure or mechanical malfunction. The pilot was conducting Part 135 operations in instrument flight rules conditions with a total flight time of 545 hours, including 59 hours of instrument time and 95 hours of night experience.
Findings
The aircraft registration N33670 was involved in the accident. The pilot's limited instrument and night experience may have been factors, but no mechanical cause was identified. The sequence of events suggests a loss of control or engine failure during the final approach phase.