Westland W30-400 Evaluated For RAAF Use

Evaluating aircraft manufacturers’ pre-sale claims on overall costs is an imprecise science at best, but while all manufacturers would no doubt argue about price relativities, it appears the Super Puma would fall about mid-way between Sikorsky and Westland on price.

Westland believes it has one advantage in pitching for the Australian order in that there are actually two customers.

Although the RAAF will buy and fly the helicopter and would like the latest flying technology available, the army dictates the capabilities it requires – which basically amounts to – a useful, robust, agile flying truck which gives the best chance of survival.

On this basis, Westland appears to have a good chance – its W30 series is based on the well-established Westland Lynx helicopter which first flew in 1971 {although commonality is not extensive) with a bigger box slung underneath – a box tailored closely to user desires.

Westland aimed for six foot headroom and got as far as 5ft in {1. 68m) by 14ft 6in long (4. 42m) and 6ft 6in wide (1. 98m), with a low door sill for easy and rapid entry and exit. Its cabin is higher, although comparable in overall size to the Black Hawk, with fewer intrusions into the cabin area. It is not as big as the Super Puma cabin, which is longer and narrower. Independent European tests have shown that the W30 can emplane and deplane fully armed troops in about half the time of the competing Puma and Black Hawk.

In the British layout of the W30 cabin, the troop commander sits at the front of the cabin facing rearwards so that he can maintain eyeball contact with all his troops seated facing inwards, as well as turning to look through the crew compartment to assess the landing zone during approach.

The Australian army however appears to take a much more independent approach and it wants all its troops to be able to orient themselves by looking out, not in, and it is not all that concerned about the squad commander maintaining eyeball contact with his men. The W30 is presently flying at a weight of 6000kg but with planned growth to over 7800kg.

The W30-100 series powered by Rolls Royce Gem engines is in full production at Westland’s Yeovil plant and additional variants are under development. The first of these is the W30- 200, powered by the GE CT? engines, designed to meet requirements for hot weather and high altitude performance.

Further variants of the W30 include the W30-400 which incorporates fully composite variable airfoil blades, a semi-rigid rotor head, new engine, and low-profile conformal gear transmission, as well as digital avionics developments, and is due to fly next year.

It is this model which is under consideration by the RAAF and RAF to replace their existing troop-carrying helicopters.

In its civil role the W30 can carry up to 17 passengers in airline-style comfort while as a military transport, it carries 14-16 in full battle gear in addition to the two crew members – a s1m1lar load to the Black Hawk.

The W30 offers considerable versatility and can be an effective tactical battlefield support helicopter in numerous roles including air mobile assault/troop transport, anti-tank, aerial mine laying, armed reconnaissance, logistic support, casualty evacuation, airborne command post and electronic warfare. The W30-400 converts readily for SAR and casualty evacuation with five stretchers plus six seated patients, and because of its height, it can be used as a mobile operating theatre.

Beyond its most immediate troop-carrying requirements, the RAAF will need gunships and under the Lynx family concept, the W30-400 will incorporate hard points to carry several different gun and missile installations including fixed forward firing guns and rockets, pintle-mounted side-firing guns, anti-tank missiles and air to air missiles.

The competing Black Hawk is not officially cleared to carry firepower since the US army does not want to give the pollies any excuse to cut into its forces of dedicated attack helicopters.

Westland planned to have crew guns firing out of the side doors but the Australian army was adamant that it did not want anything impeding the doors of its troop-carrying helicopters.

The RAF does not require guns and for Australia Westland now proposes guns firing from the rear windows of the W40. These would have a lateral field of fire of about 158 degrees as well as being able to fire almost vertically downwards at 83 degrees to spray landing zones.

The W30 as offered to the RAAF can be powered by either the GE T700 or the new ATM 322 (which is scheduled to be in fullscale production late in 1987) and can have conventional or EFIS instrumentation. With the 322, Rolls Royce and Turbomeca are taking up where the T700 leaves off. While the T700 is struggling to make 1700 SHP, the 322, which drops into the same engine mounts as the T700, has been running in pre-production trials at 1800 SHP with first production engines scheduled to run at 2150SHP. Because it is not a US item, the 322 is claimed to be about 20 per cent cheaper to acquire than the T700, and is claimed to have about 20 per cent lower SFC thereby boosting aircraft mission endurance.

Both Sikorsky and Westland have offered their machines to the RAAF with either engine, although 322 deliveries would not be possible until some time in 1988. With continuing slippage of the RAAF helicopter program, however, with a decision unlikely before mid 1986 at the earliest, this is unlikely to be a problem.

One problem with the ATM is that it could provide more power than the current W30 transmission could accept. Westland has a new advanced engineering gearbox schemed but not detail designed. Traditional gearbox designs involve large, heavy castings but Westland has patented a scheme where all loads are carried on a titanium drive shaft in a housing consisting mainly of just sheet metal to keep the oil up. Westland claims this transmits 50 per cent more power for the same gearing and is about 50 per cent lighter. The real killer requirement by the RAAF is for the helicopter to be able to take off with a full load at 4000ft at ISA plus 28 degrees (43°C) and hover out of ground effect.

Fairly obviously, the RAAF has in mind the sides of mountains in Papua New Guinea with pads dug out of near cliff faces. With the T700, the W30 becomes fuel limited to a range of less than 90nm, although if it can hover in ground effect this goes up to about 200nm.

This is not a particular concern to the Australian army, since range is not a major requirement in most operations, but with the RTM the W30 can make the requirement with no fuel limitations and IGE can have a full cabin with up to 14 troops, according to Westland.

The W30-400 series has a semi-rigid rotor head system which provides high agility without the stress problems often encountered with fully rigid rotors, even if pilots want to loop their machines. One measure of the agility that this hingeless rotor head provides is that the W30-400 can accelerate from hover to 100 knots in 8. 6 seconds and decelerate to the hover in 9. 7 seconds.

The five blades of the W30-400 main rotor incorporate varied aerofoil sections, made possible by the use of advanced Composite materials. These blades with the British Experimental Rotor Programme (BERP) “paddle” tips have a narrowing chord and built in twist to put the centre of pressure in the optimum place. With the tip of the blade at near supersonic speed, new shapes model the airflow off the tip to reduce vortices, giving about 30 per cent increase in lift and increased forward speed compared to conventional metal pocket blades.

Another Westland advance is the digital data bus system – a duplicated system in which everything runs on to and is distributed through microprocessors.

Westland claims it will be the first helicopter flying with a complete self-monitoring system though a centralised health and usage processor which will analyse continuously and put on cockpit displays everything the pilot needs to know.

The RAAF has asked for quotes on both traditional hard wiring and the digital bus – which provides the advantage that a half-life update means little more than an exchange of black boxes without rewiring.

To simplify transport by C-130, the twin engines, main transmission and rotor head of the W30-400 are mounted on a raft above the cabin. By removing three elastomeric suspension bolts and a number of self-sealing and quick disconnect couplings, this raft assembly can be removed as a single unit, utilising the helicopter’s own ground support equipment.

Teardown has been completed in two hours and re-assembled in 2. 3 hours by a standard British services team on hard stand under ideal conditions after training by factory personnel.

Under its own power, with auxiliary fuel and four crew, the W30-400’s ferry range is more than 1150km with reserves, which means a self-ferry from east to west coast of Australia would need only three refuelling stops. Once in the battle area, carrying ten combat troops and four crew, the W30-400 has a maximum cruising speed of 150 knots and a range of more than 470km, even in hot and high conditions, according to Westland.

The modular construction of the W30, rather than the whole-aircraft jig system, makes it highly suitable for dispersed production of various components, which could be a useful factor for Australian Industrial Participation (AIP).

The memorandum of understanding between Westland and Australian companies over the RAN helicopter order, which went to Sikorsky, could be resurrected if Westland won the RAAF order, although Australian companies are interested more in new technology, rather than bellies to benches, and would probably be looking for AIP work on future, rather than current projects. One problem for Westland is its rather desperate outlook as a company, particularly In the short-to-medium term. with the apparently receding chance of near-term major orders from the UK and the loss of India. Following the politically expedient awarding of the RAF primary trainer order to Shorts of Northern Ireland, Westland had generally been tipped to win the RAF order AST404 for 100 battlefield troop transport helicopters valued at about $800 million.

It has been lobbying the UK Ministry of Defence for urgent adoption of the helicopter order to keep its production line busy through to 1989, when it expects to move into full-scale production of the Anglo-Italian EH101. However UK Defence Procurement Minister, Mr Butler, recently announced that the requirement was being reviewed – a process that might take over a year.

Even more worrying, he said it was probable that the army would want a helicopter with a greater payload than those currently on offer, including Westland’s W30, the Sikorsky/ Shorts Black Hawk and Aerospatiale Super Puma.