CHI98LA180

The pilot reported that while en route at 9,500 feet msl, the engine quit and attempts to restart it were unsuccessful. The pilot picked out a field and maneuvered the airplane to a 'low key' position abeam his landing point at 1,200 feet agl. He reported extending the landing gear after low key, but when he was at the 90 degree position, he noticed a tower in the field. To avoid the tower, the pilot withheld flap extension and 'zoomed' the aircraft to clear the guy wires supporting the tower. The pilot reported that the airplane stalled at approximately 20 feet above ground level at 65 miles per hour. The engine teardown and inspection revealed broken camshaft gear drive attachment bolts. A metallurgical examination indicated that the failure was due to fatigue. The metallurgist reported the evidence of fatigue failure was exhibited by the beach marks and ratchet marks which suggested that the bolts were under torqued, thus leading to fatigue failure.

On May 29, 1998, at 1130 central daylight time, a Beech F35, N1AG, impacted the terrain during a forced landing near Orleans, Nebraska, after a loss of engine power. The pilot received minor injuries and the aircraft was destroyed. The aircraft was being operated as a personal flight under 14 CFR Part 91 when the accident occurred. The flight originated in Pueblo, Colorado, at 0930, and was en route to Hastings, Nebraska. Visual meteorological conditions prevailed at the time and a VFR flight plan was on file.

The pilot stated while the airplane was in cruise flight at 9,500 feet, VFR over southern Nebraska, he noticed a drop to 11.0 volts shown on the monitor and voltage meter. While attempting to determine the extent of the problem, the pilot heard a "pop" and lost all engine power. He attempted restart using all fuel tanks and both electrical and mechanical pumps. The engine did not restart.

While searching for a suitable landing site, the pilot secured the engine and started an emergency descent. The pilot reported that he picked out a field to land in and maneuvered the airplane to enter a "high key" position over the field at 2,300 feet agl. He reported that he flew a "low key" position abeam his landing point at 1,200 feet agl. He reported extending the landing gear after low key, but when he was at the 90 degree position, he noticed a tower in the field. To avoid the tower, the pilot withheld flap extension and "zoomed" the aircraft to clear the guy wires supporting the tower. The pilot reported that he did not have sufficient time nor airspeed to extend the flaps. The pilot reported that the airplane stalled at approximately 20 feet above ground level at 65 miles per hour. Prior to impact, the left wing dropped, the left main gear touched down first followed by the right main gear. The nose gear collapsed with subsequent prop strike and the left main spar broke.

The engine teardown and inspection revealed broken camshaft gear drive attachment bolts. Four fractured bolt segments with heads and two fractured segments without heads were submitted for metallurgical examination. The metallurgist reported some of the fractured surfaces were damaged mechanically after fracture. Low power microscopic examination of the undamaged fractured surfaces indicated that the failure was due to fatigue of the bolts. The metallurgist reported the evidence of fatigue failure was exhibited by the beach marks and ratchet marks which suggested that the bolts were under torqued, thus leading to fatigue failure.