Accident Overview
A fire tanker airplane was conducting a cross-country positioning flight when it collided with mountainous terrain while maneuvering in a canyon near the destination airport. The wreckage and surrounding vegetation were on fire upon discovery by searchers. Examination of the ground scars and wreckage debris path indicated that the airplane collided with the canyon walls in controlled flight on a westerly heading of 260 degrees at an elevation of 3,400 feet mean sea level (msl).
Witness Observations
Witnesses who held pilot certificates were positioned on a mountain top at 7,900 feet. They observed a cloud layer extending as far south as they could see, with cloud tops estimated around 5,000 feet msl based on visual cues. The clouds did not extend fully into the mountain canyons; they broke up near the heads of some canyons. When the witnesses first saw the airplane, they assumed it came from above the clouds. It was proceeding north up a canyon near the edge of breaking clouds. The witnesses were looking down at the airplane the entire time. They saw the airplane execute a 180-degree turn that was steeper than a standard rate turn. After leveling its wings, the airplane passed through one cloud, reappeared briefly, and then entered the cloud layer. It appeared to be descending when last seen. Approximately two minutes later, the witnesses observed the top of the cloud layer bulge and change to a darker color. The bulge began to subside, and several smaller bulges appeared. The witnesses notified local authorities of a possible aircraft down.
Flight Data
The operator had an Automated Flight Following (AFF) system installed on the airplane, which recorded its location every two minutes using a GPS. The data indicated that the airplane departed Prescott and flew directly to the Twentynine Palms VORTAC (very high frequency omnidirectional radio range, tactical air navigation). The flight then changed course slightly to 260 degrees, which took it to the northeast corner of the wilderness area where the accident occurred. At 1102:57, the airplane was at 11,135 feet msl traveling at 204 knots. Subsequently, the airplane made three left descending 360-degree turns, with the third turn beginning at 6,010 feet msl. The last recorded data point at 1116:57 showed the airplane at an altitude of 3,809 feet msl, heading 256 degrees, at a speed of 128 knots.
Wreckage Examination
Initial responders reported that the area was cloudy with low visibility. Examination of the accident site revealed that the airplane collided with the canyon walls in controlled flight. The ground scars and debris path were consistent with a westerly heading of 260 degrees at an elevation of 3,400 feet msl.