Possible pick-up points on crusades to empty planes (7,5)

I believe the answer is:

request stops

I'm a little stuck... Click here to teach me more about this clue!

'possible pick-up points' is the definition.
I don't know anything about this answer so I can't tell whether this works.

'crusades to empty planes' is the wordplay.
'crusades' becomes 'requests' (I can't explain this - if you can you should believe this answer much more).
'empty' says to hollow out the word (remove centre letters).
'planes' with its middle taken out is 'ps'.
'requests'+'to'+'ps'='REQUEST STOPS'

'on' acts as a link.

Can you help me to learn more?

I've seen this clue in The Independent.

Want a hint initially instead of a full solution? Install my app