The Air Tractor AT-500 is a family of agricultural aircraft that first flew in the United States on 25 April 1986, manufactured by Air Tractor Inc. Of monoplane low-wing, taildragger configuration, they carry a chemical hopper between the engine firewall and the cockpit. Compared with their predecessor, the AT-500 family featured a wingspan increase of 50 ft (15.2 m), and an additional fuselage stretch of 22 in (56 cm), allowing for a larger chemical hopper. Almost all variants offer a widened "buddy" seat or a tandem seat for a passenger, observer, or loader; trainer aircraft with full dual controls have also been offered.
From 2011 through 2018, the AT-502B was the world's top-selling agricultural aircraft with 388 deliveries, while the combined AT-500 line (AT-502A, -502B, and -504) was among the world's most popular fixed winggeneral aviation single-turboprop aircraft families, with 470 delivered—a total exceeded only by the Pilatus PC-12 and the Cessna 208 Caravan family during that time.[1]
Upgraded AT-501 with 680 shp (510 kW) Pratt & Whitney Canada PT6A-15AG or 750 shp (560 kW) PT6A-34AG engine, one or two seats, gross weight of 6,500 lb (2,900 kg) or 8,000 lb (3,600 kg) depending on production date and wing spar type[3]
AT-502A
Hot and high version of AT-502 with 1,100 shp (820 kW) PT6A-65AG or 1,050 shp (780 kW) PT6A-60AG engine, one or two seats in tandem or side-by-side arrangement, gross weight of 8,000 lb (3,600 kg)[4][5]
AT-502B
Main production version, development of AT-502 with 750 shp (560 kW) PT6A-34AG engine, one or two seats in tandem or side-by-side arrangement, gross weight of 8,000 lb (3,600 kg)[6][7]
AT-502XP
Updated AT-502A with 867 shp (647 kW) PT6A-140AG engine[8][9]
AT-503
Production version with 1,100 shp (820 kW) PT6A-45R engine, tandem seats, gross weight of 8,000 lb (3,600 kg)[10]
AT-503A
AT-503 with 750 shp (560 kW) PT6A-34AG engine, tandem seats[11] dual controls, AT-501 wings[12]
AT-503T
Dual-control trainer version of AT-503 with shorter AT-401 wings, tandem seats[citation needed]
AT-504
Dual-control trainer version of AT-502B with side-by-side seating, replaced tandem-seat AT-503 trainers, introduced 2009[13][14]