Air Tractor series
Country of Origin
United States of America
Series of piston & turboprop powered agricultural aircraft
The Air Tractor was designed by company founder Leyland Snow who earlier designed the Snow S-2 (built by Rockwell and Ayres). The initial Air Tractor model was the Pratt & Whitney R-1340 radial powered AT-301 which established the Air Tractor series' basic configuration. First flight was in 1973, and 600 were built. The PT6 turbine powered AT-302 introduced in 1977 was replaced by the AT-402. The R-1340 powered AT-401 introduced a greater span wing and increased chemical hopper capacity and first flew in 1986. The AT-402 is similar other than its 505kW (680shp) PT6A turboprop engine, the AT-402B has increased span wings. The AT-502A (first flight Feb 1992) is based in the 402B but has a far more powerful 820kW (1100shp) PT6A-45R turbine driving a slow turning five blade prop. Its excess power reserves allow high speed or high altitude operations. The AT-502B has Hoerner wingtips and optional equipment including GPS. The 5.4 tonne MTOW PT6 powered AT-602 first flew on December 1 1995 and became available for delivery in the second half of 1996. The larger and heavier two seat AT-802 and single seat AT-802A are the largest purpose designed single engine ag aircraft in production. First flight was in October 1990. The AT-802F is a dedicated firefighting version.
AT-301 - One 447kW (600hp) Pratt & Whitney R-1340 radial engine driving two blade Hamilton Standard or Pacific Propeller or three blade Pacific Propeller props. AT-502 - One 507kW (680shp) Pratt & Whitney Canada PT6A series turboprop, optionally a 560kW (750shp) PT6A, driving a three blade constant speed prop. AT-802 - One 1062kW (1424shp) PT6A-67R or 67AF driving a five blade constant speed Hartzell prop.
AT-301 - Max speed 266km/h (144kt), econ cruising speed 225km/h (122kt). Initial rate of climb 1600ft/min. AT-502 - Max speed at sea level 290kmh (155kt), typical operating speeds 195 to 235km/h (105 to 125kt). Initial rate of climb 1080ft/min. AT-802 - Max speed 338km/h (182kt), max cruising speed 314km/h (170kt). Initial rate of climb 800ft/min. Range with max fuel 805km (434nm).
AT-301 - Empty 1656kg (3650lb), loaded 3130kg (6900lb). AT-502 - Empty 1870kg (4123lb), max takeoff 4175kg (9200lb). AT-802 - Empty equipped 2860kg (6300lb), max takeoff 7260kg (16,000lb).
AT-301 - Wing span 13.75m (45ft 2in), length 8.23m (27ft 0in), height 2.59m (8ft 6in). Wing area 25.1m2 (270sq ft). AT-502 - Wing span 15.24m (50ft in), length 9.91m (32ft 6in), height 2.99m (9ft 10in). Wing area 27.9m2 (300.0sq ft). AT-802 - Wing span 17.68m (58ft 0in) length 11.07m (36ft 4in), height 3.35m (11ft 0in). Wing area 36.3m2 (391.0sq ft).
One pilot and for AT-503A and AT-802 passenger or observer. Various size chemical spray hoppers, ranging in capacity from 1210 litres (AT-301) and 1515 litres (AT-401) upwards.
Over 1500 Air Tractors of all models have been built, including more than 600 AT-301s, 245 AT-401s, 200 AT-402s, 400 AT-502s and 50 AT-802s and AT-802As.
Air Tractor series
The backbone of this section is from the The International Directory of Civil Aircraft by Gerard Frawley and used with permission. To get your own copy of the book click here.