Last night I looked here and there (including the Internet Archive, which has OED, but I think it’s the 1913 edition, which might not say much about aircraft stuff), and concluded the following (even though I cannot boast of Acadian heritage): me, I don’t know.
I can’t help but wonder–just wonder, not yet believe–whether the sense in question involves escaping the confinement (i. e., the figurative jail) of the aircraft. Again, just wondering.
But not just hay comes in bales, you can have a bale of wood, bale of paper, bale of clothes, bale of cotton, bale of cloth etc. all of can be tossed out of an airplane. Cargo was often baled up for transportation.
There is also the archaic meaning of bale,
noun Archaic. evil; harm; misfortune. woe; misery; sorrow.
If you do have the misfortune of having to bale out of an aircraft, you may be full of sorrow.
Just another one to add to the mix, if a business was going bad, would you.
“bail out” or “bale out”? would you stay or would you go?
Of course. I understood the previous poster to be saying the use of the term “bail/bale out” predates the use of airplanes for such things, though. Then again, I suppose bales were also tossed out of wagons.
What if a sheep behaved baa baa-dly and was arrested and the British bulldog magistrate required said sheep to relinquish a quantity of woof woof wool? Released on bail or on bale? The sheep’s in the dock, so probably the former?
I like @tempogain’s link above because it’s the only argument that examines all the uses of the different terms/meanings.
(emphasis mine)
The American usage of just getting out of an undesirable situation, not specifically a plane, was the one the OP used which caused all this hullabaloo, so bail is probably correct.