I lived in Tonbridge during the war and around 1946 our school Army Cadets had a camp at Manston although not on the actual airport which was RAF.
A couple us 14 year olds decided to cross the runways to have a look at Spitfires on the RAF tarmac. As far as I can recall there were no guards to be seen so we simply hopped the fence at the field where we were camped in tents and walked on the aeodrome.
FIDO pipes were crawled over and we started to cross a runway. Next minute we saw a formation of Spitfires apparently going around. Suddenly RAF guards with rifles arrived and with eminent restraint told us to go back from whence we came. We did as we were told and it was then we found the Spits had indeed gone around when ATC had warned the pilots of some kids in Army uniform about to cross the landing runway. The guards would have been entitled to kick our bums but they were gentlemen and let us go with a gentle admonishment.