Somatogravic: All Was Well for a Pilot, and Then It Suddenly Wasn’t

Illusion can occur during rapid acceleration and deceleration in flight.

Peter Garrison

Tuesday, May 27, 2025 at 07:49 AM ET

Verified

Edited By:

Travis Tingle

Somatogravic illusion (SGI) is a stealthy killer. [Shutterstock]

Key Takeaways:

A Citation 501 crashed in May 2021, killing seven people, shortly after takeoff, with the NTSB attributing the accident to spatial disorientation caused by the somatogravic illusion during initial climb.
The pilot, despite holding a type rating, had limited actual instrument experience and reportedly struggled with instrument flying, situational awareness, and the aircraft's autopilot.
The incident highlights that spatial disorientation can fatally affect seemingly capable pilots even in benign instrument conditions, stressing the critical need for unwavering reliance on flight instruments.

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In May 2021, seven people died when a Citation 501, N66BK, crashed into Percy Priest Lake near Nashville, Tennessee, shortly after taking off.

It was a little before 11 a.m. There was an overcast at 1,300 agl (1,850 msl), but no precipitation and good visibility below the clouds. The pilot had topped off the plane for the two-hour flight from Smyrna Airport (KMQY) to Palm Beach International Airport (KPBI) in Florida. After taxiing to Runway 32, he was instructed to turn to a heading of 090 after takeoff and maintain 3,000. His IFR clearance, which he had received previously, said to expect a climb to FL 330 10 minutes after departure.