Background
The intended seeding area was a rectangular flooded rice paddy measuring approximately 1,650 feet east-west by 800 feet north-south. Its western bank was 95 feet east of a river. Dense timber, generally 70 feet tall, covered the western side of the river, and a line of trees lined the eastern bank. The pilot conducted an aerial inspection and coordinated with two markers stationed on the paddy banks for seeding runs.
Sequence of Events
The initial seeding run was eastward, approaching over the timbered area toward a low sun. A subsequent westward run was followed by a steep pull-up and turn over the trees. A third eastward run began but no seed was dispensed, possibly due to difficulty observing the western marker. The fourth run, westward, appeared normal, again followed by a steep pull-up and turn. During this turn, the aircraft reached an estimated 100 feet above the trees, higher than previous turns, perhaps from an attempt to observe both markers for alignment. The aircraft then initiated a steep descent with wings level, consistent with preparing for an eastward seeding run. Seconds later, about 250 feet short of the paddy, it struck the upper branches of a tree that extended roughly 20 feet above the surrounding canopy, tearing off the starboard elevator. Without apparent power reduction and with little directional change, the aircraft rolled steeply left, descended, and after another 150 feet struck a second tree on the river's east bank. The impact tore off the wings and empennage; the fuselage fell through the tree to the ground and burst into flames.
Investigation
Investigators determined that the evidence was insufficient to identify a definitive cause. However, the operation was conducted in a manner that left minimal margin for error in the pilot's judgment of obstacle clearance.