sentences:  Owing to its advanced aerodynamics, two were used as research aircraft, one by the Royal Aircraft Establishment and one by Napier's, who used it for development of the Napier Rapier engine.At the outbreak of the Second World War, the majority of the surviving Couriers were impressed into the RAF, who used them for communications purposes.Only one Courier survived the War, being used for joyriding at Southend-on-Sea before being scrapped in December 1947.