Military Users- Spanish Air Force, Spanish Republican Air Force.
The González Gil-Pazó GP-1 was a single-engine, two-seat open cockpit training aircraft, built in Spain in the 1930s to compete for a government contract.
Declared the winner, production was curtailed by the Spanish Civil War.
The first aircraft produced from the collaboration between Arturo González Gil y Santibañez and José Pazó was the Gil-Pazó No.1.
It was, like all of their aircraft, a low-wing cantilever monoplane.
It was built of wood and metal with plywood skinning, seated two and had an unfaired conventional undercarriage.
Reportedly similar to the Miles Hawk, it was powered by an ADC Cirrus engine.
Almost no specifications are known, apart from a loaded weight of 778 kg (1715 lb).
It first flew in June 1932 and was last recorded at Cuatro Vientos, Madrid in July 1936.
In 1934 the Director General de Aeronáutica issued a specification for a two-seat trainer and Gil-Pazó’s response was the GP-1.
This “supremely elegant” aircraft, with two open cockpits and a trousered undercarriage was reportedly somewhat like the Miles Hawk Major in appearance.
Its wings, of semi-elliptic plan, had a wooden structure and a stressed plywood skin.
Flaps were fitted.
The fuselage was a steel tube structure, fabric covered at the rear with dural skinning forward.
For its first flight in June 1934 it was powered by the same Cirrus engine as the No.1 but this was replaced by a 145 kW (195 hp) Walter Junior inverted inline engine for the trainer contract competition.
The competitive trials, against the Loring X, the Hispano HS-34 and the Adaro 1.E.7, assessed the Gil-Pazó GP-1 as the clear winner, so in 1936 González Gil and Pazó received an order for 100 aircraft.
These were to be built by AISA, the former Talleres Loring factory at Carabanchel Alto, Madrid.
None of these had been completed by July 1936 at the start of the Spanish Civil War, and with rebel forces approaching Madrid in October, AISA retreated to Alicante.
About forty GP-1s were built there during the war in a collaboration with Hispano-Suiza.
Length: 8.5 m (27 ft 11 in)
Wingspan: 11.6 m (38 ft 1 in)
Wing area: 18 m2 (190 sq ft)
Empty weight: 525 kg (1,157 lb)
Gross weight: 880 kg (1,940 lb)
Power plant: 1 × Walter Junior 4-cylinder air cooled inverted in-line piston, 145 kW (195 hp)