Working as a stewardess and jumping ship? (5,1,4)

'stewardess and jumping ship?' is the definition.
I don't know anything about this answer so I cannot tell whether it can be defined by this definition.

'working as a' is the wordplay.
I cannot quite see how this works, but
'working' could be 'doing' (I've seen this before) and 'doing' is present in the answer.
'a' is within the answer.
The remaining letters 'bunk' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).

Can you help me to learn more?