Page:CAB Accident Report, United Airlines Flight 21.pdf/44



In view of the reported engine trouble earlier in the flight and of the actions of the airplane immediately prior to the crash, the question was presented whether engine failure might have contributed to the accident. Therefore, extreme care was taken in the handling, inspection and disassembly of the engines. After a preliminary inspection at the scene of the crash the engines, in the custody of Air Safety Investigators of the Board were removed to the United hangar at the Chicago Municipal Airport for disassembly and minute inspection.

During the removal operations the engine were kept in the same position as that in which they struck the ground, in order to retain any water in the carburetors or in the blower sections which might indicate malfunctioning of the engines because of the ice accumulation in the carburetors. The record indicates that the removal was accomplished with such care that water which had filled a hollow-headed plug on the outside of one of the cylinder heads on the left engine was still present at the time of disassembly. The carburetors were dismounted and tested for water by straining the gasoline remaining through a chamois. Two drops of water were found in a half pint of gasoline taken from the carburetor of the left engine. No water was found in one pint of gasoline taken from the carburetor of the right engine. The intake valve ports, cylinders and the blower section of the left engine were inspected for traces of water but none was found. A similar inspection of the right engine disclosed no evidence of water in the valve ports or the blower section but six drops of water were found in the No. 4 piston, six drops of water in the No. 4 cylinder, and about three drops of water in the