The amazing flying RAF bicycle - I think it was mine.  Spoilers made from NDT cardboard (backing card from X-Ray sheet film),
2 inch black tape, and a developer stirring paddle.  Left to right:  Charlie Gunter, Self, John Lewis and John Angel ("Jangle").
Taken at the back of the Photo Section at RAF Akrotiri.
The pillars support the roof of the old MFPU (Mobile Field Processing Unit) shelter.