What happened
The aircraft was conducting a visual flight rules (VFR) final approach as part of a practice instrument flight. A commercial pilot holding an instrument rating occupied the left seat and flew the instrument portion of the flight. During this phase, she declined the instructor's offer to land, citing her lack of proficiency.
As the aircraft reached the final approach segment, the instructor in the right seat allowed the airspeed to decay excessively after flap deployment. This loss of speed resulted in an inadvertent stall. The aircraft subsequently mushed into the ground.
The investigation
The examination focused on the flight dynamics during the final approach phase. Evidence indicated that the pilot in the left seat had relinquished control of the landing decision due to proficiency concerns. The instructor, occupying the right seat, managed the aircraft's energy state during the flare and descent.
Findings
Contributing factors included the low airspeed maintained by the instructor during the final approach and the resulting aerodynamic stall. The pilot's lack of proficiency in landing contributed to the decision to decline the landing opportunity earlier in the flight. The primary causal factor was inadvertent stall due to excessive speed decay.
Safety message
Instructors must maintain adequate airspeed during practice approaches, particularly when the student pilot is not executing the landing. Energy management is critical on final approach to prevent stalls.