What happened
The incident occurred on Theordore River, a waterway characterized by significant navigational challenges. The river features a maximum width of approximately 90 feet and lacks long straight sections, with few runs exceeding 400 feet in length. The channel is defined by numerous sharp turns, some exceeding 150 degrees, and shallow depths that can drop to as low as 18 inches during low tide.
The pilot elected to initiate takeoff while the tide was receding. At the time of departure, the water current was flowing at a speed between 7 and 9 knots. The pilot later stated that he misjudged the speed of the river relative to his aircraft's ground speed and maneuvering capabilities.
While performing a step turn to navigate around a bend in the river, the aircraft's right wing made contact with the river bank. This impact caused the floatplane to roll over. Anticipating the imminent collision with the bank, the pilot initiated a water loop maneuver in an effort to mitigate potential injuries during the rollover.
The investigation
The investigation focused on the environmental conditions and the pilot's account of the maneuver. Key findings included:
- The river width was limited to about 90 feet, restricting available turning radius.
- Current speeds were recorded at 7 to 9 knots during receding tide.
- Shallow depths of 18 inches posed a risk of grounding or restricted clearance.
- The pilot admitted to misjudging the river's speed, which contributed to the loss of control during the turn.