Piper PA-25 Pawnee Agricultural Aircraft:-

The PA-25 Pawnee was an agricultural aircraft produced by Piper Aircraft between 1959 and 1982. It remains a widely used aircraft in agricultural spraying and is also used as a tow plane, or tug, for launching gliders or for towing banners. On April 15, 1998, The New Piper Aircraft, Inc. officially sold the PA-25 series aircraft to Latino Americana de Aviación S.A in Argentina. The sale included all drawings, engineering data, parts inventory, tools, catalogs, and manuals. All support of any nature became the responsibility of the new owners. The USA type certificate for the PA-25 Pawnee is currently held by LAVIA ARGENTINA S.A. (LAVIASA).

Design and development

The PA-25 Pawnee was designed by Fred Weick  as a rugged, easy to maintain agricultural aircraft. The Pawnee is a single-engined low-wing monoplane constructed of steel tubing and covered with fabric. The emphasis of this design was on pilot safety with the fuselage structure designed to collapse progressively during a low speed crash, typically experienced during crop spraying operations.

Early models of the Pawnee had a single fuel tank located between the agricultural hopper and the engine. The NTSB recommended to Piper Aircraft that the early model PA-25's with a fiberglass fuel tank be retrofitted with a rubber fuel cell to minimize the chance of catastrophic failure and postcrash fire resulting from a crash. The later Pawnee D version featured twin fuel tanks mounted in the outer wing panels, further improving crashworthiness.

A useful design aspect was the ability to carry a mechanic on a jump seat fitted in the hopper to assist with operations at remote stations.

General characteristics

Crew: One

Capacity: 120 US gal (568 l) or 1,200 lb (545 kg) of chemicals

Length: 24 ft 9 in (7.55 m)

Wingspan: 36 ft 2 in (11.02 m)

Height: 7 ft 2 in (2.19 m)

Wing area: 183 ft² (17.0 m²)

Empty: 1,457 lb (662 kg)

Loaded: 2,900 lb (1,317 kg)

Maximum takeoff: 2,900 lb (1,317 kg)

Powerplant: 1 x Lycoming O-540-B2B5, 235 hp (175 kW)

Performance:-

Maximum speed: 102 kts (188 km/h)

Range: 300 miles (500 km)

Service ceiling: 13,000 ft (3,963 m)

Rate of climb: 630 ft/min (192 m/min)(at MTOW)

Wing loading: 15.9 lb/ft² (77.5 kg/m²)

Power/Mass: 0.0810 hp/lb (0.133 kW/kg)