Green’s Dictionary of Slang

an escape from prison.

1940		W.R. Burnett High Sierra in Four Novels (1984) 309: All I thought about was a crash out. I tried it once. [Ibid.] 310: ‘Thinking up another crash?’ ‘Maybe.’.
1948		H. McCoy Kiss Tomorrow Goodbye in Four Novels (1983) 83: He was the last guy I would have picked as a partner in a crash-out.
1955		‘Blackie’ Audett Rap Sheet 77: It was a nosy neighbour telling these friends of Thayer’s about our crash-out from McCook. [Ibid.] 96: There were six of his buddies inside who was raring to go, just as soon as they could rig a crash-out.