The flight instructor and the commercial pilot receiving instruction were conducting a local training flight to practice aerodynamic spins.
A review of air traffic control radar track data established that the Cessna 172 entered two aerodynamic spins during the flight. The first aerodynamic spin began at 10,300′ mean sea level (msl), and the airplane descended about 1,000′ before it recovered into a climb.
The airplane then made a series of climbing turns until reaching 10,800′ msl where it entered a second aerodynamic spin. The airplane did not recover from the second spin before it descended below available radar coverage at 6,800′ msl (about 1,700′ above the ground).
Multiple witnesses reported seeing the airplane descending in a nose-down spin. One witness stated that the airplane completed about five turns in the spin before it descended behind a tree line into a reservoir near Berthoud, Colorado. Both pilots aboard died in the crash.
The airplane’s Pilot Operating Handbook specified that at least 1,000′ of altitude loss should be expected for a one-turn spin and recovery and that a six-turn spin and recovery may require more than twice that altitude loss because the airplane can develop a rapid rate of rotation and a steep nose-down pitch attitude.
A post-accident examination revealed no evidence of a mechanical malfunction or failure that would have precluded normal operation during the flight.
Additionally, the examination did not identify any foreign object debris that would have limited full movement of the flight controls during the flight, and the airplane’s weight and balance were within the specified limits to conduct aerodynamic spins.
It is likely that the pilots did not apply prompt and/or correct flight control inputs to adequately recover from the intentional aerodynamic spin.
Probable cause: The failure of the pilots to apply prompt and/or correct flight control inputs to adequately recover from the intentional aerodynamic spin.
NTSB Identification: CEN17FA111
This February 2017 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.