Early in its life-cycle the airplane developed a reputation of crashing. Crew members referred to it as a "widowmaker". Some would not fly in the C-133, since the cause of the crashes was unknown. Several issues were discovered after crash investigations. The first issue was with the auto-pitch controller on the propellers. A time delay was added to relieve stress on the nose casing. The second issue was that the stall characteristics gave little warning to the crew. The left wing was found to stall before the right wing. The fix was simple,
a small strip of metal was attached to the right wing causing it to stall simultaneously with the left wing. As the aircraft neared the end of its 10,000-hour life-cycle the last C-133B crash occurred on 6 February 1970. It was determined the airframe split at the cargo door. The final fix was a band around the airframe to strengthen; the end of the C-133 was near. The C-5A Galaxy debuted in 1971 and marked the end of the C-133. Of 50 aircraft built, nine were lost in crashes and one was destroyed in a ground fire. ;13 April 1958:AF Serial No. 54-0146, 1607 ATW — Destroyed 13 April 1958, crashed south of
Dover AFB, Delaware in
Ellendale, Delaware. ;10 June 1961:AF Serial No. 57-1614, 1501 ATW — Destroyed 10 June 1961, crashed into the
Pacific Ocean off
Japan. ;27 May 1962:AF Serial No. 57-1611, 1607 ATW — Destroyed 27 May 1962, crashed into water near Shad Intersection (37° 43' N 73° W), east of Dover AFB, Delaware. ;10 April 1963:AF Serial No. 59-0523, 1501 ATW — Destroyed 10 April 1963, crashed while in traffic pattern,
Travis AFB, California. ;13 July 1963:AF Serial No. 56-2005, 1607 ATW — Destroyed 13 July 1963 during refuelling ground fire, Dover AFB, Delaware. ;22 September 1963:AF Serial No. 56-2002, 1607 ATW — Destroyed 22 September 1963, crashed into Atlantic Ocean near Shad Intersection (37° 43' N 73° W), ;7 November 1964:AF Serial No. 56-2014, 1607 ATW — Destroyed 7 November 1964 in crash on takeoff at
CFB Goose Bay, Labrador. Probable cause was a power stall on takeoff due to icing or possibly aerodynamic instability of the aircraft. ;11 January 1965:AF Serial No. 54-0140, 1607 ATW — Destroyed 11 January 1965, crashed into water after takeoff from
Wake Island. ;30 April 1967:AF Serial No. 59-0534, 1501 ATW — Destroyed 30 April 1967, ditched off the east coast of
Okinawa, Japan after propeller pitch became fixed, due to electrical problems in either propeller control or propeller power circuits. ;6 February 1970:AF Serial No. 59-0530, 60 MAW — Destroyed 6 February 1970, disintegrated in flight over southwestern
Nebraska, due to catastrophic propagation of old skin crack hidden under paint to a total length of ; large sections of skin peeled off and the aircraft came apart at . ==Surviving aircraft==