Accident Summary
A private pilot was transporting friends to an unimproved airstrip located on a riverbank for a fishing trip. The airplane, carrying four occupants, conducted two slow passes over the landing area at an altitude of about 2 feet above the ground. On the second pass, a witness observed that the right engine cowl was unsecured. Following the pass, the airplane began a climb and initiated a right turn. The witness reported that the upper wing stalled, causing the airplane to invert and descend vertically into the ground. Impact occurred at approximately 60 degrees nose-down. The four occupants sustained fatal injuries, and the wings and fuselage of the airplane experienced extensive structural damage.
Witness Account
A pilot who had previously landed at the airstrip observed the accident sequence. He noted that the airplane made the two low passes in opposite directions and that a tailwind was present during the maneuvers. On the second pass, he saw the right engine cowl was unsecured. During the initial climb after the pass, the airplane turned to the right, then stalled and inverted. The witness described the final descent as "vertical into the ground."
Flight Observations
Several pilots in the area reported hearing the accident pilot making routine position calls on the common traffic advisory frequency (CTAF) while in the airstrip's pattern. A video recorded by the right front seat passenger confirmed that the right engine cowl came open during the flight to the airstrip. The video also showed that the pilot did not appear overly concerned about the unsecured cowl. The airplane's owner stated that no known mechanical anomalies existed prior to the accident flight.
Weight and Balance Data
An approximate weight and balance calculation indicated that the airplane was at or near its maximum gross weight at the time of the accident. Additionally, the center of gravity was at or near the aft limit. These calculations suggest the airplane's loading was close to its certified limits.