Page:CAB Accident Report, United Airlines Flight 21.pdf/72

 the time Captain Scott made his approach, he probably had poor visibility from the cockpit due to ice, mist, or light snow.

The reported visibility was one mile but the visibility from the cockpit was probably much less. It is entirely possible that under these conditions Captain Scott was so intent upon endeavoring to see ahead or take some action to improve his visibility from the cockpit that he failed to give full attention to flying the airplane. This may also have contributed to his failure to perceive the warning, if any, of the incipient stall.

The testimony of eye-witnesses is fairly conclusive of the fact that as the left wing of the aircraft dropped, Captain Scott attempted to correct the stall by the use of power. Most of these witnesses saw the wing drop and then heard the power applied but the time interval was described by these witnesses as being very short, in most cases estimated to be less than one second. It is highly probable that the power was applied almost simultaneously with the dropping of the wing.

If the aircraft was being flown very close to its stalling speed and power applied suddenly, the failure of one engine to respond would be sufficient to precipitate a stall. If the aircraft had already stalled and one engine failed upon the application of power in an attempt to recover, the stall would be aggravated. However, even if both engines responded to the opening of the throttles after a power-on stall had developed, the effect would not be sufficient for recovery within the altitude available to Captain Scott. A stall induced by any of these circumstances would cause the airplane to execute the maneuvers described by the eye-witnesses and, therefore, we cannot conclude solely on the basis of the maneuvers executed by