Instituto de Pesquisas Technológicas / IPT IPT-4
Companhia Aeronáutica Paulista CAP-1 Planalto / CAP-3 / CAP-6
IPT-4(CAP-1) Planalto
The Technological Research Institute constituted the technical base on which Companhia Aeronáutica Paulista emerged. It was the Paulistinha project, passed on to Companhia Aeronáutica Paulista (CPA) together with the Planalto plane that generated the first royalties paid to the IPT.
The IPT-4 was designed by Clay Presgrave do Amaral of Instituto de Pesquisas Tecnológicas (IPT). The project had been initiated under the designation IPT-4 and although the design work had been contracted to CAP, IPT insisted on a wing profile of its own choosing that led to serious stability problems in the final product. It was a low-wing single-engine, for pilot training. The structure was made of wood, with plywood and canvas coverings. It was equipped with a 90-horsepower Franklin engine. The pilot and instructor in tandem open cockpits with fixed tailwheel undercarriage.
Clay do Amaral was part of the first board of the Companhia Aeronáutica Paulista, and IPT-4 became CAP-1, called Planalto.
First flying in June 1942 (prototype registration PP-TFW), successful test of the aircraft made it possible to sign a contract for the production of 20 aircraft. Since the institute did not have its own production facilities, the contract was handed over to Companhia Aeronautica Paulista (CAP). As a result, production aircraft were already produced under the designation CAP-1 Planalto.
The CAP-3 replaced the CAP-1's Franklin 4AC engine with a de Havilland Gipsy with double its power in the mid-40s, but the stability problems remained unaddressed until CAP engineer Oswaldo Fadigas redesigned the wing in the CAP-6. The firm attempted to sell this latter type to the Ministry of Aeronautics, but succeeded only in selling conversion kits for the existing CAP-1s and -3s in the military's inventory.
IPT-4 Planalto
Engine: Franklin 4AC-199-B3, 90 hp
Seats: 2
Engine: Franklin 4AC-199-B3, 67 kW (90 hp)
Wingspan: 8.6 m (28 ft 3 in)
Wing area: 12 sq.m (130 sq ft)
Aspect ratio: 6.16:1
Length: 6.4 m (21 ft 0 in)
Height: 2.6 m (8 ft 6 in)
Empty weight: 335 kg (739 lb)
Gross weight: 570 kg (1,257 lb)
Cruise speed: 155 km/h (96 mph, 84 kn)
Stall speed: 85 km/h (53 mph, 46 kn)
Endurance: 2.5 hours
Crew: 2
Engine: Gipsy