Diagram of the route of flight.  From the CAA Air Safety Board report.

    Investigators found that the #6 cylinder of the left engine had separated and was found nearly 3000 feet northwest of the airport boundary.  Closer inspection revealed the failure of the hold down studs from fatigue.  The separation of the cylinder, and destruction of the piston and articulating (connecting) rod resulted in the lower third of the cowling ring to be forced off.

    Because both propellers were controlled by a single propeller pitch control, the pilot was unable to increase the pitch to reduce the drag load of the dead propeller.  The combined drag and yaw from the propeller in fine pitch, and the displaced cowling caused the airplane to lose airspeed and altitude until the airplane contacted the ground.

A drawing featured in the 29 March 1939 edition of The Daily Oklahoman, showing how the cowling was forced open.  © The Daily Oklahoman

  

The Crash Site Today

 

Today, the Oklahoma City Air Terminal is known as Will Rogers World Airport.  The location of the crash site is on the grounds of the Mike Monroney Aeronautical Center.

      The airfield has changed quite a bit in the decades since this crash.  In 1941, construction began for a new Army base to be named Will Rogers Field.  What may have remained of the Braniff crash was obliterated during this time (and a new era for the airfield began).  The primary use of the field was for training of light bomber (A-20/DB-7) and reconnaissance (F-4/5, F-7) crews.  The Army decomissioned the base in 1946 and, two years later, the western portion (in the photo above) became the Oklahoma City Aeronautical Center for the CAA (now the FAA's Monroney Center).  A large building is now situated on the area where the DC-2 crashed.