Thanks for all the comments so far....
The contract is very clear.
Yes, it does decrease during the year (in a 'sliding scale' fashion). So if you leave six months after your recurrent, you pay half of the recurrent cost (plus incidentals.... hotac, flight, rental car etc).
What I am most uncomfortable with is that the bond "re-engergises" after every single recurrent. So, even if you give them ten years solid service, you are still liable for the balance of the recurrent you take with you.
Is this really how contracts are heading these days? For me, this is the first I have seen of it.
LPM.