Ayres Thrush

The Ayres Thrush, formerly the Snow S-2, the Aero Commander Ag Commander and the Rockwell Thrush Commander, is one of the most successful and long-lived agricultural aircraft in the world. Nearly 2,000 have been sold since the first example flew almost fifty years ago. Typical of agricultural aircraft, it is a single-seat low-wing monoplane of conventional taildragger configuration. Originally powered by a radial piston engine, most examples produced since the 1980s have been turboprop-powered.

Design and development

The Thrush was designed by Leland Snow and first flew in 1956, and before long was being produced in series as the S-2 by the company he founded, Snow Aeronautical. In 1965, the corporation and all its assets were purchased by the Aero Commander division of Rockwell, which put it into production alongside the CallAir A-9 that it had also acquired, branding both unrelated (though similar) machines as "Ag Commanders". When Rockwell dropped the Aero Commander brand, the S-2 was renamed the "Thrush Commander".

In 1977, Rockwell sold off the production rights to the aircraft and the production facility at Albany, Georgia, which were purchased by Ayres Corporation, a firm which had been built on retro-fitting turboprop engines to Thrush Commanders. On June 30, 2003, Ayres' assets were purchased by Thrush Aircraft, the current producer of the aircraft.

Ayres developed a special anti-narcotics crop-spraying version of the Turbo-Thrush for the US State Department. This version, known as the Narcotics Eradication Delivery Stystem (NEDS) featured an armoured cockpit and engine to protect against hostile ground fire. Nine were sold to the State Department in 1983-85. Ayres also attempted to market a militarised version as the Ayres Vigilante, intended for the Close Air Support role, but this failed to attract customers.

Variants

Snow Aeronautical

(per Simpson, 2005, p. 39)

• S-1 - initial prototype with open cockpit
• S-2 - pre-production version of S-1, three built
• S-2A - initial production version, powered by Continental engine - 73 built
• S-2B - S-2 powered by 450 hp Pratt & Whitney R-985 - 19 built
• S-2C - refined production version - 214 built
• S-2C-600 - S-2C re-engined with Pratt & Whitney R-1340-AN1
• S-2D - 6,000 lb take-off weight - 105 built

Aero Commander

• S-2D Ag Commander

Rockwell

• Thrush Commander 600
• Thrush Commander 800 - powered by Wright R-1300

Marsh

• S2R-T Turbo Thrush - Rockwell Thrush Commanders converted to turbine power by Marsh Aviation using Garrett-AiResearch TPE 331-1-101 engines

Ayres

• S-2R 1340 - equivalent to Thrush Commander 600
• S-2R 1820 or Bull Thrush
• Pezetel Thrush - powered by PZL-3
• S-2R-T - turboprop powered versions equipped with Pratt & Whitney Canada PT6

Specifications (Thrush Commander 600)

General characteristics

• Crew: one pilot
• Capacity: 370 US gal (1,514 l) or 3,270 lb (1,487 kg) of chemicals
• Length: 29 ft 5 in (8.95 m)
• Wingspan: 44 ft 4 in (13.51 m)
• Height: 9 ft 2 in (2.79 m)
• Wing area: 326 ft² (30.3 m²)
• Empty: 3,700 lb (1,680 kg)
• Loaded: lb ( kg)
• Maximum takeoff: 6,000 lb (2,720 kg)
• Powerplant: 1x Pratt & Whitney R-1340, 600 hp (450 kW)

Performance

• Maximum speed: 140 mph (225 km/h)
• Range: 405 miles (648 km)
• Service ceiling: ft ( m)
• Rate of climb: 900 ft/min (225 m/min)
• Wing loading: lb/ft² ( kg/m²)
• Power/Mass: hp/lb ( kW/kg)