Page:CAB Aircraft Accident Report, Allegheny Airlines Flight 371.pdf/10

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airport. The landing gear was in the down position except for the right main gear which was in transit to the up position. The power increase was initiated at the same time the aircraft was turned to the right just prior to hitting the mountain. It is believed that if in fact the captain had initiated an abandoned approach all of these things would have been started immediately upon encountering instrument conditions and that the captain would also advise by radio that the approach was being abandoned

Human Factors

The autopsies of the crew members eliminated all but one physiological factor which could have contributed to this accident.

The finding of atherosclerosis in the first officer's coronary arteries required a detailed study of the possibility of an incapacitation of this individual, and possible subsequent interference with the operation of the aircraft at a critical segment of its landing approach.

The existence of the epidural hematoma (150 cc.) when considering the effect of the traumatic amputation of the lower extremities and the other internal injuries indicates that this individual survived the crash. In addition, the examination of the heart and its tissue showed no ev1dence of any old or recent heart tissue damage. There is no evidence of incapacitation of the first officer prior to the crash or that incapacitation was a factor in this accident.

Conclusions

The captain made a normal instrument approach during which time the aircraft, its powerplants, systems, and its instruments functioned properly.

After completing the instrument approach the captain began his landing approach to the field but ceiling and visibility restrictions prevented him from landing on the initial landing approach to the field and a right circling approach to runway 27 was commenced. During the base leg of the circling approach to runway 27 it is probable that the caging switch of the fluxgate compass was accidentally actuated by the foot of the crew member occupying the jump seat thereby inducing an error of approximately 80 degrees to the right into the fluxgate compass system.

During the final segment of the circling landing approach the captain referred to his instruments owing to reduced weather visibility and cockpit field of vision limitations, and decided to roll out on and to hold the runway heading, either to effect a landing or to break out over the field in an area where he believed visual contact flight could be accomplished.

After proceeding on the indicated heading of 270 degrees for a short period the aircraft entered solid instrument conditions in which the aircraft proceeded for approximately 14 seconds. During this time the captain noted an apparent discrepancy between the MDI and the other directional instruments. He then caged the fluxgate compass while in level flight and upon the completion of the caging cycle determined that he was proceeding on a heading of approx1mately 190 degrees and as he started a right turn the aircraft crashed on Bald Eagle Mountain.