Aircraft Accident/Incident Report

San Carlos, Arizona 85550
Tuesady, June 3, 1997 10:40 MST

The aircraft was on a routine fire reconnaissance patrol. There were no eyewitnesses to the accident. Air Route Traffic Control Center (ARTCC) radar data showed no primary or secondary targets at or above 3,000 feet AGL. No record was found that either crew member initiated an emergency transmission. No weather phenomena was observed by any source in the area. The aircraft crashed at the apex of a river bed in a narrow canyon at an elevation of 5,620 feet MSL, and came to rest on a sandbar with a measured 400-foot radius bend in the river. The wall on the west side of the river rises steeply to about 6,100 feet MSL, and the terrain on the east side rises to equal heights over a slightly longer horizontal distance. The trim speed of the aircraft was computed by Beech Aircraft at 120 knots based on the elevator trim tab position in comparison to the gross weight and CG. A 73-degree bank angle is required for the aircraft to make a 400-foot-radius turn at 120 knots. The aircraft stall speed at that bank angle is 111 knots. An extensive postcrash fire consumed the aircraft and no ground scars were observed outside of the immediate area of the main wreckage. According to a Hartzell Propeller report, both propellers were operating symmetrically at blade angles in the governed range during the impact sequence. No preimpact failures or system/component malfunctions were found. A review of past reconnaissance flights over this same route disclosed that the flight's position reports and computed ground speed was consistent with all past flights.

The pilot's failure to maintain an adequate airspeed while maneuvering, which led to an inadvertent stall/spin.