Accident Overview
A night mail flight operating on final approach to Kansas City Airport crashed a few miles short of the runway. The pilot encountered engine problems during the approach and subsequently lost control of the aircraft. The crash resulted in the destruction of the airplane and the death of the pilot.
Sequence of Events
The flight was conducting a night mail delivery and was on final approach when the pilot experienced engine difficulties. Control was lost, leading to an uncontrolled collision with the ground. The accident occurred under conditions of icing, including sleet and freezing rain, with weather slightly worse than forecast.
Probable Cause
The official investigation determined the probable cause to be an uncontrolled collision with the ground during initial approach, resulting from a combination of factors: powerplant problems caused by vacuum pump failure; the pilot-in-command failing to maintain flying speed; airframe ice; ice on the windshield; icing conditions including sleet and freezing rain; weather conditions slightly worse than forecast; the pilot was aware of the icing conditions; and the left vacuum pump failed at an undetermined time, limiting de-icing capabilities.