The pilot had returned to the reservoir after his third water bombing run and was in the process of scooping another load of water. He stated that the water on the reservoir appeared smooth with some evidence of catspaws, or wind gusts, on the surface. He estimated his speed at touchdown to be between 70 and 75 knots, with a left quartering tailwind blowing from 3 to 5 knots.

After touching down, the aircraft had been on the water about 2 to 3 seconds when he began to advance the throttle to takeoff power. The aircraft pitched forward from 3 degrees nose up until it reached about a 1-degree nose up attitude. As the pitch changed, he increased back pressure on the elevator control.

The pilot said that about that time the aircraft encountered an approaching gust of wind that was visible on the surface of the water. He then heard a loud pop and felt a sudden decelerative force that forced him forward in his seat. The nose of the aircraft began to bowsuck and he attempted to apply more back pressure; however, the aircraft did not respond. The cockpit floor split open and water began rushing into the cockpit between both crewmembers.

During the accident sequence, the cockpit separated from the aircraft and the crew found themselves underwater. The pilot reached down and unfastened his lap belt, blew air bubbles, and then followed them to the surface. The copilot also unfastened his lap belt, saw light through the water, and swam toward it until he surfaced under the aircraft's wing.

When the landing gear is retracted, the nose gear doors close and are then secured in that position with locking pins. The pins extend aft from the hull into a mycarta block attached to the leading edge of each door. Pin movement is initiated by a hydraulic actuator that is controlled by a sequencing valve that is activated as the gear is raised or lowered. The copilot reported that the landing gear light was illuminated, indicating to him that the pins were in place.

Safety Board investigators found that the left nose gear door locking pin had separated from its hydraulic actuator. The pin was later found lodged in a fold of metal in the cockpit. It displayed a bend that dimensionally corresponds to the guide when the pin in the retracted position. The bend also prevented investigators from reinserting the damaged pin back through the pin guide.

The right nose gear door locking pin remained attached and was found in the extended position. Both nose gear doors were separated from the hull and displayed crushing and tearing. The left mycarta block remained attached to the door and was undamaged.

The aircraft logbooks were onboard the aircraft at the time of the accident and were not recovered.