What happened
On August 5, 2018, a Cessna 414, registration N727RP, was conducting a business flight near Santa Ana, California. While approaching John Wayne-Orange County Airport (SNA), the pilot communicated with the air traffic controller regarding landing runway options. After initially declining a shorter runway (20L), the pilot changed his mind less than a minute later and accepted the runway.
Following instructions to perform a left 270° turn to enter the traffic pattern, the aircraft entered a left bank. Shortly after, the pilot transmitted an emergency call. Flight data from the aircraft's ADS-B device indicated that as the left bank increased, the airspeed dropped significantly. The aircraft entered a steep, nose-down descent with a vertical speed reaching approximately -5,250 feet per minute.
The airplane impacted a shopping mall parking lot approximately 1.6 miles northwest of the airport, striking several unoccupied vehicles before coming to rest. The accident resulted in 5 fatalities.
The investigation
Investigators examined the wreckage and flight data. The aircraft's engines and airframe showed no evidence of mechanical failure that would have prevented normal operation. Both propellers showed signs of rotation and were not in a feathered position at the time of impact.
Flight data revealed that the airspeed decreased to approximately 59 knots during the turn. According to the Pilot's Operating Manual, the stall speed for the aircraft at a gross weight of 6,350 pounds was between 80 and 81 knots in a level configuration, and significantly higher in steeper banks.
Examination of the wreckage showed the landing gear was in the extended position and the flaps were set to approximately 10°. The fuel load was sufficient for the flight, and the fuel was found to be clear of contaminants.