Ayres Thrush
# Ayres Thrush

The Ayres Thrush, formerly the Snow S-2, Aero Commander Ag Commander, and Rockwell Thrush Commander, is an American agricultural aircraft produced by Ayres Corporation and more recently by Thrush Aircraft. It is one of the most successful and long-lived agricultural application aircraft types in the world, with almost 2,000 sold since the first example flew 67 years ago. Typical of agricultural aircraft, it is a single-seat 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, designed by Leland Snow, 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 of 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.

The S-2 and its several variants have been purchased by agricultural spraying operators in many countries. Large numbers are operated in the United States and Australia, while other countries using the type include Costa Rica, France, Guyana, Iran, Israel, Jamaica, the Netherlands and the United Kingdom.

Ayres developed a special anti-narcotics crop-spraying version of the Turbo-Thrush for the United States Department of State. This version, known as the Narcotics Eradication Delivery System (NEDS) featured an armored cockpit and engine to protect against hostile ground fire. Nine were sold to the Department of State between 1983 and 1985. Ayres also attempted to market a militarized version as the Ayres Vigilante, intended for the Close Air Support role, but this failed to attract customers. IOMAX USA of North Carolina, which had previously modified Air Tractor AT-802 agricultural aircraft as reconnaissance/attack aircraft, has developed the Archangel attack aircraft modeled on the S-2R-660. The United Arab Emirates has ordered 24 Archangels, with delivery from June 2015.

Two Thrush 510Gs were modified to perform a counter-insurgency role by the Austrian company Airborne Technologies at the direction of Erik Prince, the former head of Blackwater, but in the absence of an export license the aircraft have not been used operationally.

## Variants

### Snow Aeronautical

(per Simpson, 2005, p. 39)

**S-1**


    initial prototype with open cockpit.

**S-2**


    pre-production version of S-1 – 3 built.

**S-2A**


    initial production version, powered by Continental engine – 73 built.

**S-2B**


    S-2 powered by 450 hp (340 kW) Pratt & Whitney R-985 – 19 built.

**S-2C**


    refined production version, wingspan increased 4 feet 6 inches (1.37 m) – 214 built.

**S-2C-600**


    S-2C re-engined with Pratt & Whitney R-1340-AN1.

**S-2D**


    6,000 lb (2,700 kg) take-off weight – 105 built.

### Rockwell

**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 TPE331-1-101 engines.

### Ayres

**S-2R 1340**


    equivalent to Thrush Commander 600.

**Pezetel Thrush**


    powered by PZL-3.

**S-2R-T**


    turboprop powered versions equipped with Pratt & Whitney Canada PT6A.

### Thrush Aircraft

**Thrush Model 510G**


    General Electric H80 powered

**Thrush Model 510GR**


    Honeywell TPE331 powered

**Thrush Model 510P**


    Pratt & Whitney Canada PT6A-34 powered

**Thrush Model 550**


    Pratt & Whitney Canada PT6A-65AG powered

**Thrush Model 710**


    Pratt & Whitney Canada PT6A-65AG powered

**Archangel**


    Thrush 550G modified as two-seat armed attack aircraft. 1,600 shp (1,200 kW) PT6A-67F engine. Fitted with 6 hardpoints for 6,000 lb (2,700 kg) of external stores.

## Specifications (Thrush Commander 600)

Data from Jane's All The World's Aircraft 1976-77

General characteristics

* Crew: one
* Capacity:
   * 400 US gal (330 imp gal; 1,500 L) liquids or
   * 3,280 lb (1,490 kg) dry chemicals
* Length: 29 ft 2 in (8.89 m)
* Wingspan: 44 ft 4 in (13.51 m)
* Height: 9 ft 2 in (2.79 m)
* Wing area: 326.6 sq ft (30.34 $m^2)$
* Empty weight: 3,700 lb (1,678 kg)
* Max takeoff weight: 6,900 lb (3,130 kg)
* Fuel capacity: 106 US gal (88 imp gal; 400 L)
* Powerplant: 1 × Pratt & Whitney R-1340 Wasp 9-cylinder air-cooled radial engine, 600 hp (450 kW)
* Propellers: 2-bladed Hamilton-Standard 12D40 metal constant speed propeller

Performance

* Maximum speed: 140 mph (230 km/h, 120 kn)
* Cruise speed: 124 mph (200 km/h, 108 kn) (70% power)
* Stall speed: 66 mph (106 km/h, 57 kn) (at 6,000 lb (2,700 kg), flaps down)
* Ferry range: 403 mi (649 km, 350 nmi) (70% power)
* Service ceiling: 15,000 ft (4,600 m)
* Rate of climb: 900 ft/min (4.6 m/s)
