Incident Overview
During an aerial application flight, the pilot initiated a slow turn to the left while scanning for the flagman. As the aircraft maneuvered, it 'began to fall,' according to the pilot. He rolled out of the turn but was unable to maintain flight. Full power was applied, and the pilot attempted to jettison the chemical load, but the dump lever was blocked by the pressure valve lever, which had been improperly positioned.
Forced Landing and Noseover
The ensuing forced landing occurred in soft, muddy terrain, resulting in the aircraft nosing over. The owner of the airplane reported that the pilot had been on the ground for approximately 20 minutes with the engine idling prior to the flight. During the subsequent takeoff, the engine did not develop full power. The owner further stated that he had cautioned the pilot about clearing the engine before takeoff.
Examination of Aircraft Systems
Investigation revealed that the chemical dump lever was obstructed by the pressure valve lever, which was not in its correct position. This blockage prevented the pilot from dumping the load during the emergency.