I used to visit Gibraltar frequently when I was flying Argosys in the RAF. DC-3 G-AMFV used to fly to Tangier and back several times a day for Gibair. One night, some of the RAF lads had too many beers, got a tin of paint and a brush and painted "YO" in front of GIBAIR. The crusty old captain was less than happy when he did his walk-around in the morning.