Service career of the Westland Sioux Scout AH.Mk.1

[simmie]

In 1964 the British Army carried out a series of flight tests in order to procure a new light observation helicopter, to replace the Saunders Roe Skeeter.  After testing a number of types the Army selected the Bell Model 47G Sioux.  There were some mechanical problems, but the aircraft generally gave a good account of itself.  However there were concerns about of its performance and fragility in a battlefield environment.  The order was placed for 250 aircraft, the first 50 coming from Agusta, the rest coming from Westland who had obtained a license from Agusta.  As they were delivered, the aircraft were issued to Army Air Corps units across the globe.  Soon where ever the British Army was operating a Sioux could be found flying in support.

At the end of 1962 British forces were being drawn into a new crisis in the Far East.  Britain had proposed a federation of Malaya, Sarawak, Singapore, Brunei and North Borneo in May 1961.  This was strongly opposed by left wing nationalists and Indonesia.  A revolt inspired by Indonesia broke out in Brunei; this was rapidly crushed by British forces airlifted in by 205 Sqn Shackletons.  Indonesia's response was to begin training a 'volunteer' guerilla army.  Later this support was expanded to the use of Indonesian regular forces.

From the beginning of what became known as the Indonesian Confrontation, Sioux's operated in support of the security forces with units such as the 3 Commando Brigade Air Squadron, flying patrols over the jungle, watching for incursions by guerilla units.  However, after the loss of the 6th aircraft in 1963, brought down by small arms fire, in the vicinity of a protected village.  The questions about the fragility of the aircraft were brought dramatically to the fore, by a less than polite memo the Squadron Commander fired off to Major General Walker, C.O of the Borneo Defence Force.  General Walker passed the memo with a few of his own observations to Army Air Corps headquarters at Middle Wallop at the ease at which their aircraft were being brought down.  AAC HQ had privately believed that this was a possibility and had requested Westland to make a study into how the aircraft could be made 'bullet proof'.  The AAC also studied what else was being done around the world, through the use of Jane's All World Aircraft particularly the 1964-65 Ed.  In September 1963, Bell unveiled to the public the Model 207 Sioux Scout, a flying mock up of a high performance light close support helicopter, to demonstrate and investigate in practical form Bell's ideas regarding armed rotary winged aircraft and tactical use.  As this aircraft was a private venture, the company was happy to let the AAC look over the concept.  The aircraft was unarmored but did carry an Emerson Electric TAT-101 powered turret under the nose, fitted with 2 7.62mm M60 machine guns.  It was also fitted with a pair of stub wings contained fuel tanks and provided mounting points for additional weapons.  First flight was 25th June 1963, by the end of that year it was passed to the 11th Air Assault Division at Fort Benning, Georgia.  During their time with the aircraft they discovered that the stub wings improved the high speed turning performance of the aircraft, the pilots also commented on the aircrafts abilities and requested that such an aircraft be developed promptly, with more engine power.

The army passed all that it learned from Bell to Westland, who was asked to study the possibilities of producing such an aircraft using the Sioux airframes that were passing down it production line at that time.  Westland concentrated on the provision of armour and more power than the Lycoming TVO-435-A1A of 240 shp fitted to the Sioux Scout.  It was well known that Bell had previously fitted a Sioux with a Continental (Turbomeca) XT-51-T-3 of 240 shp.  Westland was well aware that the weight of any armour plate that they installed would adversely affect the performance of the aircraft, and this was before the addition of weapons or consideration of operating conditions.

What Westland put to the Army was the installation of aluminum armour plate in the form of a bathtub that passed under and around the cockpit and engine/transmission behind it.  The chosen engine was to be a derated Turbomeca Artouste giving 400 shp.  This was to be built under licence by Bristol Siddeley.  The installation was flight tested aboard an existing AAC Sioux AH-1 that was leased back from the army in August 1964.

The Army immediately placed an initial order for 25 aircraft, for use in the armed reconnaissance role.  The 1st batch of 10 aircraft were to be based on airframes taken from the Sioux AH-1's already on the production line.  These were the first batch of aircraft to be assembled by with the batch issued the serial numbers XT-151 to XT-250.  The first Sioux Scout AH-1 lifted off at Yeovil on the 23rd December 1964 and was delivered to the Army Air Corps on the 12th March 1965.

The Army were very keen to get the aircraft out to Malaysia, so weapons clearance was pushed through with some alacrity.  This was aided by Westland delivered the remaining aircraft immediately so as to allow crews to be trained prior to being shipped out to provide armed reconnaissance for the Borneo Defence Force in their continued fight against the Guerillas.  After arrival in theatre the unit continued to work up and develop tactics whilst on duty.  The aircraft proved to be a surprise to the infiltrating guerillas.  They, initially just fired up at them as they flew over assuming that this would have the same effect as before.  When the aircraft returned fire they caused a great deal of damage both physically and psychologically to the guerillas.  They also used their weapons pylons to carry target marking rockets with which they could direct strikes by RAF Hunters.  The crews, although initially dubious of the, allegedly, bullet proof Perspex canopy, came to regard their aircraft as 'the little helicopter that could'.  With the end of the Indonesian Confrontation in August 1966, the aircraft were brought home were they set about reworking the tactics that had already been developed for use in West Germany with the British Army On the Rhine.  The remaining 15 aircraft came out of the Sioux batch issued the serials XT-824 to XT-849.  These aircraft differed from the first batch sufficiently to be designated AH-2, with improved crew protection and optics.  These optics allowed the Sioux Scouts to fire the NORD SS-11 missile, and they introduced a limited degree of night capability by the fitment of an active infra red searchlight attached to the side of the turret.  The 9 survivors of the first batch were reworked to the new standard as they underwent major servicing at Middle Wallop.

By 1982, the majority of the survivors had been placed in storage at RAF St Athan awaiting disposal.   A single aircraft was retained at A&AEE Boscombe Down for trialing new night sensor devises, another aircraft was held as part of the Army Air Corps Historic Flight.  The outbreak of hostilities in the South Atlantic almost changed this situation.  As the task force departed for the Falkland Islands, the Army launched an effort to put 15 aircraft back into the air; the other remaining airframes were to provide the spares to support them.  The first group of 5 aircraft, fitted out with the newest, passive, electro-optics that the army could get their hands on at short notice, were loaded on to the M/V Atlantic Conveyor inside a number of containers.  With the lost of the ship the Army was left to advance across the western Island to Port Stanley with only Scouts and Gazelles for reconnaissance.  The 2nd group of 6 aircraft were in the final stages of preparation, when the Argentine forces surrendered.  Further work was suspended until the Irish republic expressed interest in purchasing them for anti-terrorist border patrols.  The aircraft were delivered to the Irish Air Corps in June 1983, following a training and work up programme at Middle Wallop.  They were to serve for almost 10 years, with the loss of a single aircraft due to an RPG striking its tail rotor while patrolling the border with Northern Ireland, before being stood down for the last time in July 1991.

Here are two british aircraft, the latter during winter exercises in Norway with 3rd Commando Brigade.

[simmie]

I should have added my depest thanks to Maverick for the wonderful art work, GTX for getting the original art of the Bell Sioux Scout through the really nice people on www.secretprojects.co.uk (thanks to all of those involved there).

[thedarkmaster]

like it a lot, nice back story, top class work from all involved.

[rickshaw]

The Australian Army Aviation Corps which did operate Bell Sioux in the reconnaissance role in South Vietnam  appeared to do quite well, suffering few casualties despite the much higher intensity of the war there.