Articulo de referencia

Keystone K-47 Pathfinder

The Keystone K-47 Pathfinder was an airliner developed in the United States in the late 1920s, built only in prototype form. Design and development The Pathfinder was an attempt...

The Keystone K-47 Pathfinder was an airliner developed in the United States in the late 1920s, built only in prototype form.

Design and development

The Pathfinder was an attempt by the Keystone Aircraft Corporation to develop a civil transport version of the successful series of bombers that it was producing for the United States Army Air Corps as the LB-5 and its derivatives. Like them, it was a conventional biplane design with engines mounted in nacelles on the lower wing, but also added a third engine, mounted on the nose (as the single engine of the LB-1 had been). A passenger cabin with seating for ten was added to the fuselage.

The first Pathfinder (registered NX179) was chosen by US Navy pilots Noel Davis and Stanton Wooster for their attempt at the Orteig Prize to cross the Atlantic. The standard Liberty engines were replaced by Wright J-5s of approximately half their power. Painted yellow, the aircraft was named American Legion after the sponsors of the attempt. On 26 April 1927, a week before their planned departure, the aircraft crashed during a heavily laden test flight from Langley Field at Hampton, Virginia. Unable to climb quickly enough to clear a row of trees, Davis attempted to turn the aircraft, but lost height and was forced to land. Although he succeeded in bringing the aircraft down, he was unable to stop it as it skidded into a nearby bog and was wrecked. Davis and Wooster were both killed, the former's face crushed and the latter's neck broken. The remains of the aircraft were trucked back to Keystone, where it was rebuilt and re-registered (NC1612). It was purchased by Basil Rowe to use for his pioneering air service in the West Indies, West Indian Aerial Express, christened Santa Maria. As Pan American expanded its operations into the area, Santa Maria was chartered to fly the first of the airline's mail flights from Key West to Havana, before Pan Am purchased West Indian Aerial Express outright, and the Pathfinder along with it. The aircraft continued to fly freight for Pan Am for some years before being retired and burned at Brownsville, Texas.

The second Pathfinder (NC5317) was fitted with extensions to its lower wing that was used to carry a neon sign advertising Silver Dust laundry soap through the skies of New York City at night during 1928.

Variants

K-47
Versión inicial con motores Liberty L-12 , modificada para el intento de travesía transatlántica (1 unidad construida).
K-47A
Fotografía del avión portador de señales Keystone K-47C publicada en Aero Digest en noviembre de 1928.
El K-47 fue reconstruido tras el accidente para su uso como avión de transporte comercial, alargándose su fuselaje y la envergadura de sus alas inferiores. Posteriormente, se le instalaron motores Wright Cyclone para aumentar su velocidad máxima a 240 km/h  (150 mph  ).
K-47C
Plataforma publicitaria con una envergadura inferior aún mayor, 2 motores Wright J-5 y 1 motor Pratt & Whitney Wasp.

Especificaciones (K-47A)

Datos de Jane's all the World's Aircraft 1928 [ 1 ]

Características generales

  • Tripulación: 2
  • Capacidad: 10 personas
  • Longitud: 44  pies 4  pulgadas (13,51  m)
  • Envergadura: 20  metros (66 pies  )
  • Superficie del ala: 1150 pies  cuadrados  (107  )
  • Perfil aerodinámico : EE. UU. 45
  • Peso en vacío: 6356  lb (2883  kg)
  • Peso bruto: 10.841  lb (4.917  kg)
  • Capacidad de combustible: 300 galones  estadounidenses  (250 galones  imperiales  ; 1100  litros) / 1800  libras (820  kg)
  • Planta motriz: 3 motores radiales de pistón Wright J-5 Whirlwind de 9 cilindros, refrigerados por aire, de 220  hp (160  kW) cada uno.
  • Hélices: Hélices metálicas de dos palas de paso fijo.

Actuación

  • Velocidad máxima: 115  mph (185  km/h, 100  nudos)
  • Velocidad de pérdida: 55  mph (89  km/h, 48  nudos)
  • Alcance: 500  millas (800  km, 430  millas náuticas)
  • Velocidad de ascenso: 570  pies/min (2,9  m/s)
  • Carga alar: 9,4  lb/  pie cuadrado (46  kg/ )
  • Potencia/masa : 0,061 hp/lb (0,100 kW/kg)

Referencias

  1. Grey, CG, ed. (1928). Jane's all the World's Aircraft 1928. Londres: Sampson Low, Marston & company, ltd. pp. 232c– 233c. 

Lecturas adicionales

  • Taylor, Michael JH (1989). Enciclopedia de aviación de Jane . Londres: Studio Editions. pág.  560. ISBN 0-7106-0710-5.
  • "Pioneros y patricios" . Air Classics . Agosto de 2006. Consultado el 4 de septiembre de 2008 .
  • "Gigante Amarillo" . Time . 9 de mayo de 1927. Archivado del original el 25 de noviembre de 2010. Consultado el 4 de septiembre de 2008 .
  • aerofiles.com