Incident Overview
Two Shorts Brothers SD-360-300 turboprop aircraft were involved in a midair collision during a planned formation flight. The crews had agreed before departure to join up in flight to capture video and still images of each airplane. While flying in formation, the pilot of N3735W announced a right turn toward N372AC with a descent. During the turn, the left wing of N3735W struck the left wing and engine of N372AC.
Aftermath and Damage
Following the collision, N372AC rolled left and pitched down sharply before the flight crew regained control. The aircraft began losing hydraulic fluid and eventually suffered a complete hydraulic system failure. It made an emergency landing at a nearby airport with flaps retracted and landing gear partially extended. The airplane overran the runway end and came to rest about 100 feet beyond the departure threshold. Post-accident inspection revealed white paint transfer and scrapes on the left wing deice boot, the outboard left engine cowling crushed inboard, the left wing-strut leading edge torn open and bent, and a tear on the lower fuselage skin forward of the landing gear wheel wells, consistent with a propeller strike.
N3735W impacted terrain and was destroyed in a subsequent ground fire. The flight crew and a passenger were killed. The outboard three-quarters of the left wing separated from the main wreckage without fire damage; the upper wing surface showed diagonal linear scrapes. The left aileron from N3735W was found on the runway where N372AC had landed.
Probable Cause
The official probable cause is that the flight crew of N3735W failed to maintain clearance from another aircraft as they turned to break formation flight while maneuvering. A contributing factor was the decision of both flight crews to fly in formation.