Piper aircraft, Inc.
 Piper PA-25 Pawnee is an agricultural aircraft built between 1959 and 1981 by Piper Aircraft.

• Design and development

  Most agricultural aircraft before 1949 were converted military aircraft and it was in that year that Fred Weick, based at Texas A&M University, designed a dedicated agricultural aircraft: the AG-1. The AG-1 first flew on 1 December 1950.

  During 1953, Fred Weick was approached by Piper to become a consultant on the agricultural version of the PA-18, the PA-18A, in particular to design and test a distributor for dust and seeds. A few weeks later, Piper sponsored Texas A&M University to design a dedicated agricultural aircraft based on the AG-1 but to use as many PA-18A and PA-22 components as possible. The resulting design, the AG-3, was smaller than the AG-1 and had a steel tube fuselage which was fabric covered

  Variants

  AG-3

  Prototype built at Texas A&M University.

  PA-25-150 Pawnee

  Initial production version fitted with a 150 hp (110 kW) Lycoming O-320 engine. Payload of 800 lb (360 kg) powders or 145 US gal (121 imp gal; 550 L) liquids.

  

  

  PA-25-235 Pawnee B

  Fitted with a 235 hp (175 kW) Lycoming O-540-B2B5 six-cylinder engine. The Pawnee B featured a larger hopper and an increased payload of 1,200 lb (540 kg).

  PA-25-235 and PA-25-260 Pawnee C

  The Pawnee C was an upgraded version of the 'B' model and was available with a 235hp or a 260hp high compression version of the O-540 engine and either a fixed pitch or constant speed propeller. The fuselage of the Pawnee C featured a quickly detachable 'turtledeck' panel to ease the rinsing out of spilt corrosive agents from the fuselage structure and to facilitate servicing and inspection of components housed in the rear section of the fuselage.

Wiki Link Variants