I was just passing on the message from the AD operator who thinks the sign is fine. Interesting that the way he described it sounds quite the opposite to what you have posted!! and he said he had legal advice!!
No wonder he's had a dozen phone calls.
At least we know it's an innocent sign and should have read "no entry without a valid pilots licence" or words to that effect.
Perhaps I'll call him back again.
The woman on reception at the council offices believed it was removed due to concerns over it, but the operator said they were still there. Sounds like an organized establishment!