Airspeed AS.8 Viceroy

The Airspeed AS.8 Viceroy was a British twin-engined racing version of the Airspeed AS.6 Envoy. Only one exemplar was built by Airspeed Ltd. in Portsmouth in 1934. It was built to order of Captain T. Neville Stack and Sydney Lewis Turner to compete in the England-Australia MacRobertson Air Race.
The Viceroy was a modified Envoy with some changes. It was powered by two supercharged Armstrong-Siddeley Cheetah VI engines in long chord placed in smooth NACA cowlings. The engines yielded a power of 290 hp each.
The main landing gear was strengthened to allow for higher weight take-offs, an auxiliary petrol tank was installed in the aft part of the fuselage with capacity for 1.227 litres (270 imp. gallons) and its fuselage was modified to make it narrower and passenger windows were deleted.
The Viceroy started the race from RAF Mildenhall, in Suffolk, but, after suffering various reliability problems, some of them with the mainwheel brakes, it was withdrawn from the race at Athens. The pilots deemed unsafe to proceed and they would probably wouldn't be able of even finishing the race. A bitter set of legal actions followed with the pilots complaining that the aircraft hindered by various problems, wasn't ever really ready. Airspeed contested the action and, eventually the aircraft was returned to them without refund. The aircraft was taken back to Portsmouth and was stored until July 1936 when, the next month, it was sold to the French company SFTA (a company which bought war material to aid the Spanish Republicans) and departed to France on its way to the Spanish Civil War.
On 13th August 1936 the Viceroy reached Barcelona, being shortly taken into the Spanish Republican Air Force. It was named as "González Gil", after an aviation Captain who had died some days earlier in the skirmishes at the mountains north of Madrid. It was used for combat, reconnaissance and even bombing purposes during the first months of the conflict by the Republicans. However, due to its limitation, later was employed only for reconnaissance duties. In 1938 the aircraft was still active with the Republican Air Force, operating as a transport aircraft, however, it didn't survive the war and was destroyed in unknown circumstances shortly after.

Sources:
1. https://en.wikipedia.org/wiki/Airspeed_Viceroy
2. https://es.wikipedia.org/wiki/Airspeed_Viceroy (translated)
3. http://bioold.science.ku.dk/drnash/model/spain/did.html
4. Enciclopedia De La Aviación Militar Española  (translated)