Page:CAB Accident Report, Eastern Air Lines Flight 21.pdf/19

 Consideration has been given to the question whether ice in the carburetors could have contributed to the accident. Atmospheric conditions on the night of February 26, 1941, at Atlanta, Georgia, were such as to make carburetor icing a possibility. The ground temperature was 40 degrees Fahrenheit and the relative humidity varied from 93 percent near the ground to 100 per cent at 200 or 300 feet above the ground. Under these conditions, only eight degrees Fahrenheit expansion cooling in the carburetors would have been necessary to from ice in them which, in view of the moisture content in the air, was a distinct possibility. As found in the wreckage, the carburetor heat controls were in full "on" position and the carburetor de-icer valves were both partly open. Thus, Captain Perry had anticipated the possibility of carburetor icing and had taken stops to prevent it. Ice in carburetors of a sufficient extent to have contributed to the accident certainly would have been detected by Captain Perry because such a marked loss of power would have been immediately apparent. However, as we have pointed out, Caption Perry gave no evidence of knowledge of an emergency and took no measures to combat it. The probability of the accident being due to loss of power from carburetor ice is also refuted by the fact that for the last 1500 feet the plane is known to have proceeded in practically level flight and to have crashed with normal power being developed by the engines. Thus all of the circumstances surrounding the flight indicate that carburetor ice was not present, or, if present, was not of such a degree as to be a contributing factor in the accident.

Accordingly, it is our belief that neither a structural nor