TYPE: Agricultural sprayer.

PROGRAMME: Leland Snow designed S-1 prototype, first flown with radial engine on 17 August 1953; entered production as S-2; Type Certificate for original S2D issued 1 November 1965; SR2 followed 21 March 1968; over 1,800 built by Snow and (following 18 February 1970 transfer of Type Certificate) Rockwell. Type Certificate obtained by Ayres on 28 November 1977; Ayres introduced turboprop version, having previously specialised in turbine conversions. PT6-engined S2R-T34 certified 28 April 1977; Garrett TPE331 versions certified from 5 March 1992 (S2R-G6) onwards. Quality Aerospace obtained Type Certificate on 26 November 2001 and this transferred to Thrush Aircraft on 2 September 2003.

CURRENT VERSIONS: S2R-T11: 373 kW (500 shp) PT6A-11AG turboprop; standard 1,514 litre (400 US gallon; 333 Imp gallon) chemical hopper. Certified 26 October 1979.
S2R-T15: 507 kW (680 shp) P&WC PT6A-15AG turboprop; standard or optional 1,930 litre (510 US gallon; 425 Imp gallon) hopper. Certified 3 April 1979.
S2R-T34: 559 kW (750 shp) P&WC PT6A-34AG turboprop; standard or optional hoppers. High Gross (4,763 kg; 10,500 lb) MTOW version certified 5 November 1997.
S2R-T45: Powered by P&WC PT6R-45AG. Certified 23 July 1990.
S2R-T65 NEDS: Narcotics Eradication Delivery System; 1,026 kW (1,376 shp) P&WC PT6A-65AG turboprop and 2.82 m (9 ft 3 in) five-blade propeller; certified 3 September 1987; 19 delivered to US State Department (see Customers).
S2R-G1: Powered by 496 kW (665 shp) TPE331-1 turboprop; 1,514 litre (400 US gallon; 333 Imp gallon) hopper. Certified 29 August 1995.
S2R-G6: Introduced 1992; 559 kW (750 shp) TPE331-6 turboprop; standard or optional hopper; two 435 litre (115 US gallon; 95.75 Imp gallon) fuel tanks, with 863 litres (228 US gallons; 190 Imp gallons) usable; optional hopper capacity 1,930 litres (510 US gallons; 425 Imp gallons); pilot, with dual-cockpit option.
S2R-G10: First flown November 1992; certified 12 January 1993; CAM 8 certification; 701 kW (940 shp) TPE331-10 turboprop and four-blade propeller.
V-1A Vigilante: Surveillance and close air support version; engineering designation S2RHG-T65; certified 8 June 1988; TPE331-14-GR turboprop; first flight (N3100A) 15 April 1989. Still carries hopper; has five-blade propeller for quiet operation; four hardpoints beneath wings; can be fitted with range of equipment including loudspeaker systems for policing duties. Fuel capacity 1,136 litres (300 US gallons; 250 Imp gallons) plus optional external tank containing 1,514 litres (400 US gallons; 333 Imp gallons).

CUSTOMERS: US State Department ordered 19 S2R-T65 NEDS during 1983-88 for use by International Narcotics Matters Bureau. Vigilante used in Africa for game and poacher surveillance. By July 2001, 15 G1s, 55 G6s, 68 G10s, 39 T15s, 272 T34s and 15 T45s had been produced and over 2,500 of all versions delivered to 80 countries.
Production by new Thrush company began with 273rd T34 (c/n T34-273, N550AG), registered December 2003.

COSTS: About US$600,000, depending on engine and customer fit.

DESIGN FEATURES: Conventional crop-sprayer configuration, with hopper ahead of cockpit; cantilever low wing of constant chord; braced empennage with sweptback leading-edges; robust landing gear.
Advantages over piston-engined versions include much improved take-off and climb, 454 kg (1,000 lb) higher payload because of lower engine weight, operation on aviation turbine fuel or diesel, 3,500 hour TBO, quieter operation and ability to feather propeller without stopping engine while refuelling and reloading.

FLYING CONTROLS: Conventional and manual. Plain ailerons; servo tab in each elevator; electrically actuated flaps.

STRUCTURE: Two-spar light alloy wing with 4130 chrome molybdenum steel spar caps; welded chrome molybdenum steel tube fuselage structure covered with quickly removable light alloy skin panels; underfuselage skin of stainless steel; all-metal tail surfaces and strut-braced tailplane; metal ailerons and flaps. Extended wing, originally optional, is now standard, replacing earlier 13.54 m (44 ft 5 in), 30.34 m² (326.6 sq ft) version.

LANDING GEAR: Tailwheel type; fixed. Main units have rubber-in-compression shock-absorption and 8.50-10 (10 ply) tyres. Hydraulically operated Cleveland dual calliper disc brakes. Parking brakes. Wire cutters on main gear. Steerable, spring steel locking tailwheel, size 5.00-5.

POWER PLANT: One turboprop (see under Current Versions for engine and fuel details). All but NEDS, G10 and Vigilante have Hartzell three-blade, constant-speed, feathering and reversing propellers; usable fuel capacity 515 litres (136 US gallons; 113 Imp gallons) in 400 gallon hopper models and 863 litres (228 US gallons; 190 Imp gallons) in 510 gallon hopper models.

ACCOMMODATION: Single adjustable mesh seat in 'safety pod' sealed cockpit enclosure, with steel tube overturn structure. Tandem seating optional, with forward-facing second seat. Dual controls optional with forward-facing rear seat, for pilot training; these versions have 'DC' suffix to c/n; available since 1985. Adjustable rudder pedals. Downward-hinged door on each side. Tempered safety glass windscreen. Cockpit wire cutter. Dual inertia reel safety harness with optional second seat. Baggage compartment standard on single-seat aircraft.

SYSTEMS: Electrical system powered by a 24 V 50 A alternator. Dual lightweight 24 V 35 Ah batteries.

AVIONICS: To customer's requirements.

EQUIPMENT: GFRP hopper forward of cockpit can hold 1,514 litres (400 US gallons; 333 Imp gallons) of liquid or 1,487 kg (3,280 lb) of dry chemical, equivalent to 1.50 m³ (53.0 cu ft). Optional 1,931 litre (510 US gallon; 425 Imp gallon) hopper of 1.87 m³ (66.0 cu ft) can be installed. Hopper has a 0.33 m² (3.56 sq ft) lid, openable by two handles, and cockpit viewing window. Standard equipment includes Universal spray system with external 50 mm (2 in) stainless steel plumbing, 50 mm pump with wooden fan, Transland gate, 50 mm valve, quick-disconnect pump mount and straine. Streamlined spraybooms with outlets for 68 nozzles. Micro-adjust valve control (spray) and calibrator (dry). A 51 mm (2 in) side-loading system is installed on the port side. Stainless steel rudder cables. Navigation lights, instrument lights and two strobe lights. Windscreen washer/wiper.
Optional equipment includes a rear cockpit to accommodate forward-facing seat for passenger, or flying instructor if optional dual controls installed; space can be used alternatively for cargo. Other optional items are a Transland high-volume spreader; agitator installation; 10-unit AU5000 Micronair installation in lieu of standard booms and nozzles; Transland gatebox with stiffener casting; quick-disconnect flange and kit; night working lights including landing light and wingtip turn lights; cockpit fire extinguisher; and water-bomber configuration.