The Keystone K-55 Pronto was a

mail plane A mail plane is an aircraft used for carrying mail. Aircraft that were purely mail planes existed almost exclusively prior to World War II. Because early aircraft were too underpowered to carry cargoes, and too costly to run any "economy class" ...

developed in the United States in the late 1920s.

Design and development

The Pronto was a conventional single-bay, unequal-span biplane design with slightly staggered wings. The pilot sat in an open cockpit, in tandem with a second cockpit that could carry two passengers side-by-side. The fixed, tailskid undercarriage had divided main units. A number of these aircraft were purchased by the government of Peru. Operated by the aviation arm of the

Peruvian Navy The Peruvian Navy ( es, link=no, Marina de Guerra del Perú, abbreviated MGP) is the branch of the Peruvian Armed Forces tasked with surveillance, patrol and defense on lakes, rivers and the Pacific Ocean up to from the Peruvian littoral. Addit ...

, 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 Leonardo is a masculine given name, the Italian, Spanish, and Portuguese equivalent of the English, German, and Dutch name, Leonard. People Notable people with the name include: * Leonardo da Vinci (1452–1519), Italian Renaissance scient ...

and Harold B. Grow from

Lima Lima ( ; ), originally founded as Ciudad de Los Reyes (City of The Kings) is the capital and the largest city of Peru. It is located in the valleys of the Chillón, Rímac and Lurín Rivers, in the desert zone of the central coastal part of t ...

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 flown by Lieutenant Suero was captured by the Colombian Army.

Operators

; *

Specifications

Keystone_K-55_Pronto_3-view_Le_Document_aéronautique_April,1928

References

External links

aerofiles.com
{{Keystone aircraft 1920s United States mailplanes

Pronto Pronto, stylized as PRONTO, is the second-generation contactless payment system for automated fare collection on public transit services in San Diego County, California. The system is managed by the San Diego Association of Governments, opera ...

Biplanes Aircraft first flown in 1927

Design and development

Operators

Specifications

References

Further reading

External links