Accident Sequence
According to witness accounts and air traffic control communications, the airplane was observed proceeding westbound from the airport at a low altitude. A witness reported that the engine noise was smooth but low, and the airplane was not gaining altitude. The witness noted that the airplane flew parallel to and north of a road, and as it crossed the point of their driveway, it banked slightly, struck tree tops, and crashed and exploded.
Communications
Control tower communications indicated that shortly after being instructed to contact departure control, the pilot responded with the transmission "two hotel whiskey - engine failure." No further communications were received.
Engine Examination
An examination of the airplane's engine revealed that three teeth from the camshaft gear were fractured. An additional eight teeth were crushed, rendering the camshaft unable to be driven. A Materials Laboratory examination of the camshaft gear and fractured teeth showed that two of the three fractured teeth exhibited signs of fatigue. The third tooth showed evidence of overstress. Rockwell hardness measurements on the gear portion showed an average hardness of Rockwell 64HR30-N, whereas specification drawings indicated that the gear teeth should be hardened by gas-nitride process to a minimum of Rockwell 69HR30-N. The airplane had a new engine installed at the annual inspection on February 5, 2001, and had logged approximately 75.7 hours from that inspection to the time of the accident.