fobotsco
When Lee Jones led the RAF Aerobatic Team they were painted yellow and called the "Yellow Jacks". They scared the pants off me - particularly at the World Gliding Championships at South Cerney in 1964. They "wired the joint" at 4-6ft in criss-cross and at that height they couldn't have seen all other ac because the airfield has a distinct upside-down saucer shape
Apologies for my being pedantic, but the South Cerney Worlds were in 1965, and my photos from there definitely show the RAFAT with red Gnats, in one of their first public displays. Also, South Cerney, and surrounding land, is as flat as a pancake. Possibly you are thinking of an earlier display at Middle Wallop (which does have a pronounced hump) ?
(Oops, sorry, that's the problem with resurrected threads)