20010815020559A

(-23) During low alt. Maneuvers, a stall ocurred and the aircraft crashed & burnt at the base of a hill. (.19) on August 15, 2001, about 0700 hours mountain standard time, a Beech F-33A, N3172P, collided with terrain near Mobile, Arizona. Airline training center Arizona, inc., was operating the airplane as an instructional flight under the provisions of 14 CFR part 91. The certified flight instructor pilot and dual student sustained fatal injuries; the collision sequence and a postcrash fire destroyed the airplane. The cross-country flight departed goodyear, Arizona, about 0645 on a round-robin, low-level navigation training flight. Visual meteorological conditions prevailed and no flight plan had been filed. The operator reported that the pilots were members of the german air force and the flight was a low-level navigation training mission. The flight syllabus called for the flight to complete the route at 500 feet above ground level (AGL). The flight plan called for a southwesterly departure, two segments in a southeasterly direction, three segments in an easterly direction, and four segments to a westerly direction as the airplane re turned to goodyear. Another of the operator's airplanes, with two instructors aboard, departed immediately after the accident airplane. This aircrew planned to complete the last southeasterly and first easterly segments of the same route as the accident airplane. This crew initially flew north of the standard route at 3,500 feet then turned south to intercept it. As they turned south, they observed the accident airplane proceeding on a southeasterly course. The pilots observed the accident airplane cross a ridgeline and roll into a right bank. One pilot estimated the bank angle exceeded 60 degrees with the nose falling below the horizon. They lost sight of the airplane, and then observed a plume of smoke emerge. They turned toward the ridge and observed the accident airplane burning. The ridge, about 3 miles long and 2 miles wide, was an outcropping from the desert floor. The ridge generally ran in a north-south direction, and rose to an approximate height of 2,100 feet (MSL), which was about 600 feet above the surrounding terrain. The airplane came to rest halfway up the north face of an east-west finger. At this point, the crest of the finger was about 200 feet above the desert floor, and investigators estimated the slope at 25 degrees. The fuselage and debris path were aligned on a bearing of 250 degrees. Vegetation ranging in height between 3 feet and 20 feet, and within 5 feet to 30 feet of the wreckage, was undamaged. The primary wreckage was at coordinates 32 degrees 58.84 minutes north latitude and 112 degrees 14.39 minutes west longitude, at an estimated altitude of 1,635 feet. Investigators examined the wreckage on scene on August 15 and 16. An additional examination occurred at air transport in phoenix, Arizona, on August 17. Investigators accounted for all major airframe components and control surfaces at the accident site. They established control continuity from the control surfaces to a molten area in the center of the cabin. The engine partially separated and rotated about 45 degrees clockwise. The crankshaft fractured just aft of the propeller mounting flange; the fracture surface angled 45 degrees to the longitudinal axis of the crankshaft. The propeller separated; two blades and the hub were to the left of the engine, while the third blade was under the engine. All three propeller blades exhibited leading edge gouges and s-bends. The s eparated blade exhibited chordwise striations, polishing along its cambered side, and was bent in the direction opposite of rotation. A ground scar ran parallel to and 2 feet away from the leading edge of the wings. At the left edge of this ground scar, investigators found red lens fragments. The portion of the left wing outboard of the flap separated except for the aft spar, flipped inverted, and rotated about 60 degrees counterclockwise. The leading edge of the left wing tip crushed up about 40 degrees. The right wing rotated about 5 degrees counterclockwise. Both wings exhibited crush damage to the lower skins. A 3-foot-high bush was between the bent left wing tip and the left horizontal stabilizer; the bush was scorched but otherwise undamaged. Fire consumed the cabin and scorched the wings, forward portions of the vertical stabilizer, and the right horizontal stabilizer. Pieces of airframe and debris, such as plexiglas and insulation, not in charred areas were not sooty or discolored. Investigators identified the following pieces in the debris field. The most distant piece of wreckage found was a 3-foot-square section of top wing skin with a refueling port in it, which was a bout 30 feet forward of the main wreckage. The cabin entry door was leaning against a scorched but otherwise undamaged small tree at the 2 o'clock position from the wreckage and about 10 feet forward of the right wing tip. Three feet from the right wing tip, the battery and the right side engine cowling were under a scorched but otherwise undamaged bush. One emergency window exit frame was about 5 feet left of the propeller. The left elevator counterweight separated and was 2 feet forward of the left elevator. The outboard 2 feet of the left horizontal stabilizer was crushed up and aft.