FTW94GA076

While returning from a glider tow mission, after the glider had been released, the aircraft was observed flying at low altitude. One witness said the engine sounded as though it was cutting out. Other witnesses described the aircraft as flying erratically at low altitude. It then entered a dive and crashed in a wooded area. No aircraft system failure or malfunction was found during an investigation. An autopsy revealed evidence of coronary artery heart disease. The el paso county coroner's office indicated the accident could have resulted from cardiac arrhythmia due to coronary insufficiency. An air force Academy cadet was also aboard the aircraft, but the aircraft was not equipped with dual controls.

History of flight

On January 28, 1994, at 1550 mountain standard time, a Bellanca 8GCBC, N7634S, impacted into trees while returning to the United States Air Force Academy Airport from a local glider tow operation. The civilian contract pilot and Air Force Academy cadet passenger received fatal injuries, and the aircraft was destroyed. No flight plan was filed for this public use flight which originated at the Air Force Academy approximately 30 minutes prior to the accident. Visual meteorological conditions prevailed.

At the time of the accident, the glider tow had been completed and the aircraft was en route back to the Academy airport. According to witnesses, the tow plane was observed to be flying erratically and at a lower altitude than normal. Several witnesses observed the aircraft dive into a wooded area approximately 2 miles northwest of the Academy airport. The aircraft was equipped with a communications radio; however, no transmissions were heard by the Academy tower or other aircraft operating in the area.

Personnel information

The pilot received his last physical on June 24, 1993. The physical was a first class and included an electrocardiogram. A review of the pilot's medical history from FAA files shows annual first class physicals with electrocardiograms. The records provide no evidence of coronary abnormalities.

Wreckage and impact information

The accident site was oriented on a base track of 130 degrees. The first item was the glider tow rope followed by fractured trees and the right wing of the aircraft. The main wreckage was nose down in the trees with the nose oriented opposite the direction of travel. The left wing remained attached as did the empennage and engine.

The propeller was detached from the engine and found along the track between the right wing and main wreckage. One propeller blade was twisted towards low pitch at mid span and bent forward with the tip bent forward 90 degrees. The other blade was twisted towards low pitch along its span and the outer 6 inches was bent in an 'S' curve. The spinner was deformed opposite the direction of rotation.

Examination of the flight control system provided no evidence of preaccident failure or malfunction and flight control continuity was established.

The cockpit area remained intact and both seats remained attached to the seat rails. The front restraint system was intact and, according to available information, was removed during the removal of the pilot. The rear restraint system separated from the right sidewall and the shoulder harness was found in the unfastened position. A diagram of wreckage distribution is attached.

Medical and pathological information

An autopsy was performed on the pilot by the El Paso County Coroner's office located in Colorado Springs, Colorado. Results of the autopsy listed the manner of death as follows:

"The aircraft accident appears to have resulted from cardiac arrhythmia due to coronary insufficiency."

One of the areas listed in the final diagnosis is quoted.

"Coronary artery heart disease with: a. Occlusion, left anterior descending branch of coronary artery, arteriosclerotic, old. b. Stenosis, right coronary artery, atherosclerotic, moderate. c. Hypertrophy, heart, predominantly left ventricular (460 gm)."

Tests and research

The engine was examined under the guidance of the investigator in charge (IIC) at the facilities of the Air Force Academy. No evidence was found which would have prevented the engine from operating in a normal fashion prior to the accident.

Fuel and oil samples were taken and analyzed by the Air Force fluids laboratory. Both samples met specified standards.

Additional information

The wreckage was released to the owner's representative on February 4, 1994. No parts were retained.