Page:CAB Accident Report, 1942 TWA DC-3 and Army C-53 mid-air collision.pdf/13

 Adverse winds encountered between Columbia and Kansas City made the Army C-35 flight about 7 minutes late arriving at Kansas City and the co-pilot was preparing to so notify the Kansas City Control Tower at the time of the collision.

The collision occurred at an altitude of between 3500 and 3900 feet; slightly north of the "on" course of the northeast leg of the Kansas City Radio Range.

Both flights were intentional instrument flights and the weather otherwise had no bearing on the accident.

There was no evidence of failure or malfunctioning of any part of either aircraft prior to the collision.

In this instance, Air Traffic Control cleared the TWA DC3 to climb through the overcast, within the limits of the airway along which they knew the Army C-53 was flying, and before the Army flight had reported in over the Kansas City Range Station. Issuance of this clearance authorized the TWA aircraft to pass through the flight altitude and the probable path of of the Army aircraft. Until the Army plane had reported as over its fix at Kansas City, Air Traffic Control had no positive assurance that the TWA flight path would not intersect the Army flight path. Therefore, Air Traffic Control should have required the TWA flight to either continue into the north quadrant contact for a distance beyond the confines of the airway before starting its climb, or to remain contact until the Army flight had reported over its fix.

A study of the procedure under these circumstances indicates that it was not an established practice to require an aircraft cleared in a quadrant to proceed a specified distance into the quadrant before starting its climb, so as to clear the airway.

There usually is a lag between the actual time over a fix and the time