Piper PA-25 Pawnee

infobox Aircraft
name = PA-25 Pawnee
type = Agricultural aircraft
manufacturer = Piper Aircraft



caption = A Pawnee in use as a glider tug
designer = Fred Weick
first flight = 1957
introduced = August 1959
retired =
status = In use as agricultural aircraft and glider tug.
primary user =
produced = 1959-1982
number built =
unit cost =
developed from =
variants with their own articles =

The PA-25 Pawnee was a very popular agricultural aircraft produced by Piper Aircraft between 1959 and 1982. It remains a very widely used aircraft in the agricultural spraying industry and is also used extensively as a tow plane, or tug, for launching gliders or towing banners.

Design and Development

The PA-25 Pawnee was originally designed by Fred Weick [http://www.airliners.net/info/stats.main?id=303 Airliners.net, PA-25] ] 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.Macdonald,1964. p. 137.]

The later Pawnee D version featured twin fuel tanks mounted in the outer wing panels, further improving crashworthiness, early models of the Pawnee had a single fuel tank located between the agricultural hopper and the engine.

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. Macdonald,1964. p. 137.]

Variants

PA-25-150 Pawnee

: Initial production version fitted with a 150hp Lycoming O-320 engine. 800lb payload.

PA-25-235 Pawnee B

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

PA-25-260 Pawnee C

:The Pawnee C was an upgraded version of the 'B' model with a 260hp high compression version of the O-540 engine. 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.

PA-25-260 Pawnee D

:The Pawnee D was also powered by a Lycoming O-540 of 260hp but featured fuel tanks fitted in the outer wings and metal covered ailerons and flaps.

pecifications (PA-25-235 Pawnee)

Data from: "Macdonald Aircraft Handbook" Macdonald,1964. p. 137.]

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: 2,900lb (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)

ee also

Related development:
*Piper PA-36 Pawnee Brave
*Gippsland Aeronautics PA-25-235/A9 'Fatman'

Comparable aircraft:
*Cessna 188
*PZL-Mielec M-18 Dromader
*Ayres Thrush
*CallAir A-9
*Grumman G-164 Ag Cat
*Zlin Z-37 Cmelak

References

Notes

Bibliography

* Green, William. "Aircraft Handbook". London. Macdonald & Co. (Publishers) Ltd., 1964.

External links

* [http://www.scalesoaring.co.uk/Documentation/Pawnee/Pawnee.html PA-25 Pawnee photo gallery]