Globe Air (USA)

Following a dual engine change, the pilot test flew the aircraft. On initial climb, at about 500 feet agl, both engines began backfiring violently and lost power. According to the pilot, power sufficient for flight could not be obtained, and a forced landing was made about 0.75 miles from the airport. The landing occurred in open desert terrain and the aircraft was substantially damaged. The pilot acknowledged that he did not check the position of the control handles for the superchargers during either his preflight or pre-takeoff inspections. And the blowers had been inadvertently left set to the high blower position. According to the pilot, the checklist which he was using for the aircraft did not address the position of the blowers because for the past 15 years it had been company policy to 'wire the blowers to the low blower position.' Both occupants escaped uninjured.