The Q.6 was the first twin engine aircraft developed by Percival with a production of 26. It was fitted with DH Gypsy Six engines and flown with 2 crew and 4 passengers. This aircraft was one of four fitted with a retractable undercarriage. [The correct type description is Percival Q.6 with the designation P.16 being a post-war invention. Also, 'Petrel' was applied to those aircraft impressed for military service.] Permission & Copyright Keith Dillingham.