Blimey, they're not cheap are they? One of my brothers used to have one of these sort of things and I seem to recall the antennae was a really important part of the kit. He ended up buying a large extension one with a magnetic base that sat on top of the car roof!
He wasn't that interested in listening in but it became a battle of wills; he'd bought the bloody thing, therefore he was determined to make it work. .
Next time you have to drive by East Midlands Airport have it ready. Five to ten miles distance does not sound a long way away but the stock antennae might mean you have to be in line of sight sometimes.
Civil airbands are in the 109 to 137MHz range and military are between 225 and 400 MHz.
Does it cover these frequencies?
Edit; aha! excellent find FT. I think you're best bet is to take it to the airport and have a run through there and see how you get on.