Piper PA-25 Pawnee
Encyclopedia
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).
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.
Data from: Macdonald Aircraft Handbook
Comparable aircraft:
Agricultural aircraft
An agricultural aircraft is an aircraft that has been built or converted for agricultural use - usually aerial application of pesticides or fertilizer ; in these roles they are referred to as "crop dusters" or "top dressers"...
produced by Piper Aircraft
The New Piper Aircraft
Piper Aircraft, Inc., is a manufacturer of general aviation aircraft, located at the Vero Beach Municipal Airport in Vero Beach, Florida. Along with Beechcraft and Cessna, it is considered one of the "Big Three" in the field of general aviation construction....
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
Glider aircraft
Glider aircraft are heavier-than-air craft that are supported in flight by the dynamic reaction of the air against their lifting surfaces, and whose free flight does not depend on an engine. Mostly these types of aircraft are intended for routine operation without engines, though engine failure can...
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
Type certificate
A Type Certificate, is awarded by aviation regulating bodies to aerospace manufacturers after it has been established that the particular design of a civil aircraft, engine, or propeller has fulfilled the regulating bodies' current prevailing airworthiness requirements for the safe conduct of...
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 WeickFred Weick
Fred Ernest Weick was one of the United States' earliest aviation pioneers, working as an airmail pilot, research engineer, and aircraft designer....
as a rugged, easy to maintain agricultural aircraft. The Pawnee is a single-engined low-wing monoplane
Monoplane
A monoplane is a fixed-wing aircraft with one main set of wing surfaces, in contrast to a biplane or triplane. Since the late 1930s it has been the most common form for a fixed wing aircraft.-Types of monoplane:...
constructed of steel tubing and covered with fabric. The emphasis of this design was on pilot safety with the fuselage
Fuselage
The fuselage is an aircraft's main body section that holds crew and passengers or cargo. In single-engine aircraft it will usually contain an engine, although in some amphibious aircraft the single engine is mounted on a pylon attached to the fuselage which in turn is used as a floating hull...
structure designed to collapse progressively during a low speed crash, typically experienced during crop spraying
Aerial application
Aerial application, commonly called crop dusting, involves spraying crops with fertilizers, pesticides, and fungicides from an agricultural aircraft. The specific spreading of fertilizer is also known as aerial topdressing....
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
The New Piper Aircraft
Piper Aircraft, Inc., is a manufacturer of general aviation aircraft, located at the Vero Beach Municipal Airport in Vero Beach, Florida. Along with Beechcraft and Cessna, it is considered one of the "Big Three" in the field of general aviation construction....
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
Jump seat
A jump seat , in aviation refers to an auxiliary seat for individuals — other than normal passengers — who are not operating the aircraft. In general, the term 'jump seat' can also refer to a seat — in any type of vehicle — which can fold up out of the way; vehicles include carriages, automobiles,...
fitted in the hopper
Hopper
Hopper may refer to:-Mechanical parts:* A general term for a chute with additional width and depth for temporary storage* Hopper , a large container used for dust collection* Part of a combine harvester...
to assist with operations at remote stations.
PA-25-150 Pawnee
- Initial production version fitted with a 150hp Lycoming O-320Lycoming O-320The Lycoming O-320 is a large family of 92 different normally aspirated, air-cooled, four-cylinder, direct-drive engines commonly used on light aircraft such as the Cessna 172 and Piper Cherokee. Different variants are rated for 150 or 160 horsepower...
engine. 800lb payload.
PA-25-235 Pawnee B
- Fitted with a 235hp Lycoming O-540Lycoming O-540|-Specifications :-See also:-External links:...
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 and was available with a 235hp or a 260hp high compressionCompression ratioThe 'compression ratio' of an internal-combustion engine or external combustion engine is a value that represents the ratio of the volume of its combustion chamber from its largest capacity to its smallest capacity...
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.
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.
Accidents and incidents
- 9 August 1974 a crop-spraying Pawnee was involved in fatal mid-air collision1974 Norfolk mid-air collisionThe 1974 Norfolk mid-air collision happened on the 9 August 1974 at Fordham Fen, Norfolk, England when a Royal Air Force McDonnell-Douglas Phantom FGR2 of 41 Squadron collided with a Piper Pawnee crop spraying aircraft. All three aviators were killed, the pilot and navigator of the Phantom and the...
with a Royal Air ForceRoyal Air ForceThe Royal Air Force is the aerial warfare service branch of the British Armed Forces. Formed on 1 April 1918, it is the oldest independent air force in the world...
MD Phantom FGR2 in Norfolk, England.
- 24 April 1996 a modified Piper PA-25-150 two-seat model was involved in a fatal crash near Buffalo, MO in which an FAA flight test engineer was killed but the test pilot survived.
- 6 February 2010 a glider-towing Pawnee was involved in a multiple fatality accident near Boulder Colorado Municipal Airport after colliding with a Cirrus SR20Cirrus SR20The Cirrus Design SR20 is a piston engine composite monoplane that seats four. The SR20 is noted for being the first production general aviation aircraft equipped with a parachute designed to lower the aircraft safely to the ground after loss of control or structural failure.-Design and...
. All in both powered craft were fatally wounded, however the glider released and landed safely.
Specifications (PA-25-235 Pawnee)
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-B2B5Lycoming O-540|-Specifications :-See also:-External links:...
, 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)
See also
Related development:- Gippsland Aeronautics PA-25-235/A9 'Fatman'Gippsland GA200-External links:* *...
- Piper PA-36 Pawnee BravePiper PA-36 Pawnee Brave|-See also:...
Comparable aircraft:
- Air Tractor AT-300Air Tractor AT-300|-See also:-External links:*...
- Ayres ThrushAyres Thrush-See also:-Bibliography:* Green, William. Aircraft Handbook. London. Macdonald & Co. Ltd., 1964.* Simpson, Rod. The General Aviation Handbook. Midland Publishing. 2005. ISBN 1-85780-222-5....
- CallAir A-9CallAir A-9|-See also:-References:* Taylor, John W. R. Jane's All The World's Aircraft 1965-66. London: Sampson Low, Marston & Company, 1965.* Taylor, John W. R. Jane's All The World's Aircraft 1966-67. London: Sampson Low, Marston & Company, 1966....