On August 24, 1984, a Cessna 170B (registration N7681) was involved in an aviation accident near Poplar, MT. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A pilot reported that during a river landing with gusty tailwind, the aircraft remained on step and unresponsive to controls, leading to a flip onto its back on the riverbank.
Circumstances
The pilot detailed the landing environment: a river with a current of 12–15 mph, a landing area 100 yards wide that curved to the right, and wind gusting to 20 knots from the right rear quarter.
Approach and Landing
The approach was described as fast. Upon touchdown, the aircraft remained on step—a condition where the hull is planing on the water—and did not respond to aileron or rudder inputs intended to turn the aircraft. The quartering tailwind caused the aircraft to drift toward the outer bank of the river while the engine was at idle. The aircraft continued taxiing on step at an estimated 30 mph.
Pilot Action and Outcome
The pilot opted not to add power and attempt a takeoff again due to the strong tailwind and insufficient room to accelerate to flying speed. Subsequently, the aircraft pitched forward, flipping over its nose and coming to rest inverted on the river bank.