TYPE: Agricultural sprayer.

PROGRAMME: Developed from Weatherly 201; prototype (N9256W) first flown 1979.

CURRENT VERSIONS: 620: Initial version; no longer available.
620-B: Current piston-engined version, powered by Pratt & Whitney radial engine. Length 8.15 m (26 ft 9 in); height 2.44 m (8 ft 0 in). Slinghtly different spray equipment but same sized hopper.
620-TP: Initial turboprop version, with P&WC PT6A-11AG; no longer available.
620-BTG: Current turboprop version; engine can be retrofitted to earlier versions.
Description applies to Weatherly 620-BTG.

CUSTOMERS: By 1999, 155 Weatherly 620s of all versions had benn built. The 156th was registered in 2001; two more built by October 2003.

COSTS: 620B US$225,000; 620BTG US$360,000 (2003).

DESIGN FEATURES: High lift: drag ratio wings, with tip vanes for vortex diffusion and increase of swath width; vanes fold downwards for ground handling. Hinged wing leading-edges aid inspection.

FLYING CONTROLS: Conventional and manual. Stainless steel rudder cables.

STRUCTURE: All-metal monocoque fuselage; metal wings and control surfaces; glass fibre tail fairings. Rudder deflects ±20°; elevator 27° up and 15° down; ailerons 29° up and 11° 30' down.

LANDING GEAR: Tailwheel type; fixed. Mainwheel oleos connected to spar to disperse stresses. Spring tailwheel assembly with fully castoring and locking wheel. Three-piston Cleveland brakes. Mainwheel tyre size 8.5-10; tailwheel 12.5-4.5.

POWER PLANT: 620-B: One Pratt & Whitney 336 kW (450 hp) R-985-AN radial engine driving a Hartzell HC-B3R30-4 or -4B three-blade propeller. Fuel capacity 369 litres (97.5 US gallons; 81.1 Imp gallons), of which 341 litres (90.1 US gallons; 75.1 Imp gallons) is usable. Oil capacity 25.3 litres (6.7 US gallons; 5.6 Imp gallons).
620-BTG: One Honeywell TPE331-1 turboprop, derated to 373 kW (500 shp), driving a McCauley 3GFR34C602/100LA-2 three-blade propeller. Fuel capacity 492 litres (131 US gallons; 108 Imp gallons) in seven tanks (two in each wing and three in wing centre-section) of which 439 litres (116 US gallons; 96.5 Imp gallons) usable. Oil capacity 0.6 litre (1.6 US gallons; 1.3 Imp gallons).

ACCOMMODATION: Pilot only. Four-way adjustable mesh seat. Baggage compartment behind seat.

SYSTEMS: 24 V electrical system; 50 A Jasco starter/generator in 620-B, 250A Jasco model in 620-BTG. Optional air conditioning and windshield washer/wiper.

EQUIPMENT: Agricultural dispersal system comprises a 1,344 litre (355 US gallon; 296 Imp gallon) hopper in forward fuselage, size 1.35 m³ (47.5 cu ft); Weath-Aero fan; 5 cm (2 in) SS bottom load pump; 5 cm (2 in) Agrinautics spray pump with three-way valve; 6.10 m (20 ft) pylon-mounted drop boom with nozzles every 15 cm (6 in); 63.5 cm (2 ft 1 in) Transland gate box. Main gear and cockpit wire deflectors, plus deflector cable from cabin to fin. Rinse-out system optional, as are stainless steel spray system and flow meters.