Previously BGA539. The Olympia was developed in pre-War Germany as the DFS Olympia Meise and the design was essentially copied by the Chilton Aircraft Company with production later taken over by Elliotts of Newbury. The type first flew in 1947 and a total of 150 were built, this example, a Mark 1 as shown by the skid, was from the first production batch.

"Blue John" was built by Elliotts in May 1947 as BGA503. It was registered as G-ALJP in March 1949, later reverting to BGA503.