The first Pioneer CC.1 to be delivered to the RAF, on 11 August 1953, was serialled XE512. Ironically, XE512 was essentially the prototype Prestwick Pioneer I from 1947, re-engined with the Alvis Leonides engine, and refurbished for RAF use. (Thus, VL515 became G-AKBF, and then returned to a military serial as XE512). The next three aircraft delivered (constructors numbers 102, 103 and 104) were likewise the second prototype VL516/G-ANAZ plus the partly completed third and fourth prototypes VL517 and VL518. As XE513, XE514 and XE515 they were delivered on 15 August 1953, 3 September 1953 and 10 February 1954 respectively. Two of these first batch of four are illustrated on this page.