The Agusta Bell Sioux AH Mk1 , was one of the first batch of fifty ordered by the Army Air Corps and built by Agusta SpA at Gallerate in Italy in 1964.

These aircraft were ordered as stop-gaps for the Westland-built Sioux which started coming off the Yeovil production line in the Spring of 1965. The aircraft was taken on charge by the AAC at Middle Wallop on 3 July 1964 and for the duration of her military service was used for flying training and engineering familiarisation at Middle Wallop. XT131 was transferred to the Development and Trials Flight on 18 November 1977 until being subsumed into the AHAF on 11 September 1980. XT131 was handed over to the Historic Aircraft Flight Trust on 1 February 2015 and registered as G-CICN.

The Sioux, affectionately referred to as the ‘clockwork mouse’, was distinctive for its bubble canopy, exposed welded tube tail boom and saddle fuel tanks. Its two bladed rotor made a ‘chop-chop’ sound, leading to the nickname ‘chopper’ for helicopters.

The Sioux is probably the best known of the early military helicopters earning its reputation during the Korean war (1950-1953). It is the most recognised, perhaps due to the success of the 1970 feature film, based on the 1968 novel M*A*S*H (Mobile Army Surgical Hospital) by Richard Hooker and the long-running television series.

The Sioux was the first of many helicopters within the US Army to be named after Native American tribes.

Engine Lycoming TVO 435-B1A
Speed 91kts (169kph) max, 70kts (130kph) cruise
Endurance Two hours 48 gallon (218 litre) fuel tank
Maximum All Up Weight 2950lbs (1338kg)
Display Weight 2678lbs (1215kg
Dimensions Length 40ft (12.19m)
Rotor Span 38ft (11.58m)
Capacity Pilot plus two