In reply to the OP, sometimes there is an 'honesty' system where it asks for a 'voluntary contribution' to the airfield upkeep
Unfortunately this 'honesty' system does not always work both ways. I made a trip last summer to one such place and made a contribuation (on the advice of the aerodrome operator) to the local RNLI in lieu of a landing fee, only to recieve an invoice 6 months for another landing fee as "they have changed their procedure". There 8 pilots I know personally who this happened to so I hate to think how many others were also affected!
