N2528CCessna 170B · 1954

The pilot reported that after taking off from a frozen gravel bar by a river in remote wilderness, the airplane stalled. The left main landing gear struck the edge of the cut bank and the left wing impacted the ground. The fuselage then impacted the top of the bank and spun counterclockwise. The pilot stated that the left wing was separated from the fuselage and the fuselage had sustained substantial damage.

The pilot reported there were no pre-impact mechanical failures or malfunctions with the airframe or engine that would have precluded normal operation.

The pilot reported as a safety recommendation, "I would take off empty or with minimal known weight to ensure that the aircraft would perform as planned. I could then land to reload, or if partially loaded, fly to another gravel bar that was longer, and stage from there, returning to the point of origin empty, and then continue to shuttle gear and people. That first flight would have been better planned without another person on board, not just due to weight, but due to risk to that person."

Alaska Off Airport Flight Operations

The Alaskan Aviation Safety Foundation has published a safety briefing Off Airport Landings. This safety briefing discusses off airport takeoff and landing operations. This safety briefing states in part;

When flying very low and slow on takeoff or landing approach, do not fly over an abrupt drop-off such as a cut bank or steep lake shore. You can abruptly lose ground effect and begin to settle.

This safety briefing also lists considerations when selecting off airport takeoff and landing sites and states in part;

Airplane load: Obviously, ever gram counts.

Density altitude: You don't have to go into the mountains to get a change in density altitude.

Ground drag: A thawed gravel bar, even a dry one, presents considerably more drag than a frozen one.

Departure obstacles: An obvious thing, but if you've been flying off river bars in ground effect, it's easy to underestimate the additional space needed to clear a 15 foot obstacle.