NTSB Factual Report

HISTORY OF FLIGHT

On February 18, 1995, approximately 1150 mountain standard time, a Cessna 150M, N45325, sustained substantial damage when it crashed after takeoff from runway 24 at the Burley, Idaho airport. The certified flight instructor and his student were fatally injured. There was no report of an ELT activating, and there was no fire. No flight plan was filed for the instructional flight, which was to be conducted under 14CFR91. Visual meteorological conditions prevailed at the time of the accident.

Witnesses reported that the student pilot had flown a solo flight, then had returned to the fixed base operation, where he met the instructor. According to a witness, the instructor stated that they would be going out for a series of short and soft-field takeoffs and landings, then out to the practice area for air work. A witness who observed the crash stated that "I saw the plane leaving the runway to climb to approx 2 to 400 ft. About the time the plane crossed Highland Ave the plane started a steep left hand banking turn. It stayed in this turn for about 100 feet, then turned nose down and headed straight for the ground. About half way down the nose of the plane began to come up. The plane was too close to the ground before it was able to pull out and crashed about a 45 degree down angle...."

The aircraft collided with terrain southwest of the departure end of runway 24, east of the county fairgrounds.

PERSONNEL INFORMATION

Flight time for the certified flight instructor was obtained by reviewing a log book with a final entry dated April 29, 1992. No later log books were located. According to the airman's medical records, the flight instructor had total civilian flight time of 2800 hours.

WRECKAGE AND IMPACT INFORMATION

The wreckage was located in an open field immediately east of the county fairgrounds, and on the east side of Highland Avenue, a few hundred feet southwest of the departure end of runway 24 at Burley Municipal Airport. The wreckage distribution path was oriented about 050 degrees from a half-foot deep crater, with the tail stinger approximately 48 feet from the southwest edge of the crater. The nose tire was twelve feet from the southwest edge of the crater. The propeller and spinner were 30 feet from the nose tire, and the tail cone stinger was six feet from the propeller. The ELT--separated from its antenna and mounting bracket--was found about 40 feet beyond the airframe, along the same distribution path. The left main wheel and tire were about 100 yards east of the main wreckage. Small pieces of Plexiglas, metal and composite parts were located between the crater and main wreckage.

All structural components and control surfaces (with balance weights attached) and the powerplant, with the exception of the aforementioned propeller, nose wheel, main landing gear wheel, and ELT, were at the main wreckage site. One propeller blade was twisted, with evidence of chordwise scratches. The other blade had S-type bending, with chordwise scratches on the cambered side. The propeller hub extension remained with the propeller, and had separated from the crankshaft.

The tailcone, with attached control surfaces, was largely intact aft of the rear windscreen. The vertical fin was undamaged; the rudder horn was folded over about 30 degrees to the right above the upper hinge point. The horizontal stabilizer was wrinkled about mid span on both the left and right sides, with aft spar damage. The leading edges of both wings were crushed aft with accordion folding. The left wing strut was cut about mid-span, during the recovery of the pilots' remains. The wing flaps were intact; both ailerons exhibited aftward bending outboard of the outboard hinge point. Both wing tips were crushed aftward.

Both shoulder harnesses were cut to free the occupants during the recovery operation. Aileron cables were cut during the recovery operation. Control cable continuity was verified from the tail control surfaces to the cockpit controls. Wing access panels were removed and continuity of aileron and flap cables through the wings was established. The flap selector was destroyed. The elevator trim tab was 2 degrees down. The flaps were retracted, and the fuel selector was in the on position.

Residual autogas was found in both fuel tanks. The fuel system had been compromised by impact damage, with fuel lines separated.

The throttle was in the idle position, mixture was rich (1/4 inch aft), the primer was in and locked and the magneto switch was in the both-on position.

The nose of the aircraft exhibited aft crushing with the floor folded upward about mid point of the door orifice. The tailcone remained attached to the fuselage, but was displaced downward.

MEDICAL AND PATHOLOGICAL INFORMATION

Autopsies were performed on both pilots by Dr. Fisher of the Pocatello Medical Center, Pocatello, Idaho. Toxicological testing was performed on samples from both pilots by the FAA, with negative results for cyanide, ethanol, and drugs, except for the detection of nicotine metabolite in the blood and urine of the flight instructor.

Anatomic diagnosis in the autopsy report for the student pilot listed "fracture dislocation, metacarpal bones, left hand." Anatomic diagnosis in the autopsy report for the flight instructor noted "fracture of the right forearm near (the) wrist."

TESTS AND RESEARCH

The aircraft was moved to the fixed base operator's hangar after the on-scene investigation was completed. The powerplant was inspected for evidence of pre-impact mechanical discrepancies. The engine was intact, with the carburetor and vacuum pump separated. The oil slump was pushed to the rear and the left magneto was partially separated. The top spark plugs and valve covers were removed and the crankshaft was rotated. Continuity of the drive train was confirmed for all cylinder and to the accessory section. Compression was noted on all cylinders. Both magnetos sparked at all terminals when hand rotated. The oil screen was coated with clear oil.

The carburetor was disassembled and inspected. The carburetor heat was jammed in the full cold position; the throttle valve was free; the mixture control was broken but free to move. At disassembly, a small quantity of auto gas was found in the bowl. Both floats were dented.

No pre-crash mechanical discrepancies were found during on-scene investigation. Fuel was found in both fuel tanks and in the carburetor bowl. Fueling records were not kept by the fixed base operator for their training aircraft.

ADDITIONAL INFORMATION

The wreckage was released to the owner's representative at the flight instructor's Burley airport facility on February 19, 1995.

NTSB Probable Cause

THE FAILURE OF THE DUAL STUDENT TO MAINTAIN AIRSPEED WHILE MANEUVERING, AND THE FLIGHT INSTRUCTOR'S INADEQUATE SUPERVISION.