NTSB Identification: WPR11FA050
14 CFR Part 91: General Aviation
Accident occurred Wednesday, November 17, 2010 in Payson, UT
Probable Cause Approval Date: 11/22/2011
Aircraft: DIAMOND AIRCRAFT IND INC DA20-C1, registration: N978CT
Injuries: 2 Fatal.

NTSB investigators either traveled in support of this investigation or conducted a significant amount of investigative work without any travel, and used data obtained from various sources to prepare this aircraft accident report.

During the dual instructional flight, the airplane entered a spin and made numerous descending rotations before impacting at a 44-degree nose down angle onto a residential driveway. Sounds consistent with engine operation during the descent were reported by witnesses. The aircraft wreckage was located directly under a designated practice area. The floor of the practice area was 2,500 feet above ground level (agl) and the upper altitude limit was 5,500 feet agl. According to the flight school director of operations, typical work done in the high-altitude working areas included stalls, slow flight, and steep turns. Examination of the airplane wreckage revealed that the flaps were in-between the takeoff and landing position; flap deployment is consistent with slow flight or stall practice.

The intention of the instructional flight was to prepare the student for his private pilot practical examination. According to records maintained by the flight school, a majority of the student pilot's flights had been with the accident instructor; however, the certified flight instructor (CFI) provided extremely little documentation on the actual performance of the student during the flight portion of his training. A similar stall and spin event occurred 2 weeks prior to the accident where the same CFI and a different student lost control of the airplane during a slow flight practice; however, in that instance, the CFI was able to recover the airplane quickly. The CFI's most recent spin training was conducted 7 years prior to the accident, although the flight school required instructors to complete a flight check every 12 months for each course of training they were approved to teach.

The flight school that operated the training flight did not have a functional mechanism to track safety incidents or a well advertised way for the students or staff to anonymously report aviation safety concerns. The director of safety did not convene regular safety meetings. Flight school management did not require CFIs to create written commentary regarding each student’s performance. There was a perception by three of the four chief flight instructors that CFI proficiency flights were not encouraged, and the CFIs were discouraged from using company flight time to maintain proficiency.

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

The pilots' failure to maintain adequate airspeed during a slow flight maneuver that resulted in a stall and spin, and the flight instructor’s delayed or improper remedial actions to recover from the spin. Contributing to the accident was the flight school’s inadequate safety program.

Full narrative available

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