Keystone K-55 Pronto
The Keystone K-55 Pronto was a mail plane developed in the United States in the late 1920s. It was a conventional single-bay, unequal-span biplane design with slightly staggered wings. The pilot sat in an open cockpit, in tandem with a forward cockpit that could carry two passengers side-by-side. The fixed, tailskid undercarriage had divided main units.
Pronto was the first aircraft Keystone made for the civil market. However, like many aircraft manufacturers of the late 1920s - early 1930s, this attempt was not successful. A number of these aircraft were purchased by the government of Peru. Operated by the aviation arm of the Peruvian Navy, these aircraft initiated the first airmail service into the Peruvian Amazon. The first flight of this service was made by two Prontos, piloted by Leonardo Alvariño Herr and Harold B. Grow from Lima to San Ramón on 26 October 1927.
At least one Peruvian Pronto was fitted with pontoons and used to survey the Amazon River for locations suitable for seaplane operations.
In the Colombia-Peru War one Peruvian K-55 flow by Lieutenant Suero was captured by the Colombian Army.
Engine: 1 × Wright J-5, 220 hp (160 kW)
Wingspan: 39 ft 11 in (12.17 m)
Length: 26 ft 9 in (8.15 m)
Empty weight: 594 kg
Maximum take-off weight: 1100 kg
Maximum speed: 112 mph (180 km/h)
Cruising speed: 160 km / h
Range: 500 miles (800 km)
Crew: One pilot
Capacity: 2 passengers