There only 1 or two forces in the UK that employ civlilian Air Observers. 1 of the South East Units comes to mind. They have aprox 3 out of 9 as civvies. They are never flown alone, ie without a cop on board too.
The situation may change over time, as civilianisation creeps further and further into the Police Service. Civilian Observers across the board may prove impossible to resist.
In the meantime, the job is dominated by (experienced) serving Officers. IF you want to join the cops, better be prepared to do Police work..!!