A New Truck For Wallaby Airlines

There is a lot of research to be undertaken before a final decision can be made on even the simplest equipment choice. Even politics has to be taken into consideration – witness the Carl Gustav anti-tank missile fiasco in the 1960s when Sweden refused to replenish spares due to Australian involvement in Vietnam.

Therefore, when a requirement is tabled that appears to suit one individual aircraft then you have an aerospace marketing manager’s dream.

The requirement I refer to is that of a replacement for theRAAF’s DHC4 Caribou and C47 Dakota aircraft. The obvious, and heavily tipped, choice is the Caribou’s big brother, the DHC5D Buffalo.

Indeed the Buffalo is everything the RAAF and Army could hope for in a short/medium range STOL airlifter operating in a true STOL environment under hostile con­ ditions. In Vietnam. No. 35 Squadron (termed Wallaby Airlines by appreciative allied ground forces) operated their Caribous into and out of strips that many ground commanders thought impossible. Particularly the Americans who relied more heavily on larg r transports (C130, etc) and massive use of helicopters. In Vietnam the message or what was required was learnt the hard way and, for once, we were fortunate to be operating the best eguipment available.

Today the Tactical Transport requirement {though officially, and somewhat surprisingly, the actual DOD re­quirement is classified!) is for an aircraft that is basically a much improved version of the Caribou concept, nothing more, nothing less. There are other contenders, of course, yet the improved DHC5D is well ahead on points – let us have a closer look at the Super Buffalo.

DeHavilland Canada’s DHC5D Buffalo is a much im­ proved version of the original DHC5A version which first flew way back in 1964, not long after the first Caribou squadron became operational at RAAFRichmond. The DHC5D “Super” Buffalo features uprated engines, minor structural im­ provements, increased payload and overall improvements in operational capabilities and maintenance requirements.

The Buffalo is so heavily favoured for several specific reasons. Firstly, it can operate from totally unprepared strips with payload and clear a 50 foot obstacle with a 1000 foot roll. Secondly, the Buffalo is proved in service operation in a varie­ ty of operating environments. From the steaming jungles of the Amazon to the Canadian Arctic through to the rugged mountains of Peru. Thirdly, Hawker DeHavilland are beautifully set up to commence assembly of all aircraft at their Bankstown, Sydney, facility. Fourth, the air force knows theCaribou and what it can do, therefore introduction of its bigger brother would not present the overall problems that would inevitably arise through purchase of a totally “new” aircraft such as the G222 or Transall C160.

Powerplant is the improved General Electric CT64-820-4 turboprop which produces a full 3133shp at takeoff. This is around 350shp more per engine than was available with the earlier A version, guaranteeing vastly improved air lift perfor­ mance at hot and high conditions. Each T64 drives a 14. 5ft diameter Hamilton Standard constant speed, full feathering propellor. Multiple low pitch blades are fitted to permit steep STOL approaches and fixed angle reversing provides ex­ cellent braking and control on the ground. Furthermore, the Buffalo propellors have integral hydraulic systems and elec­ trical de-icing on the spinners, cuffs and blades. The T64 is a modern, high pressure ratio, free turbine with a very low weight (1145Ib) and outstanding fuel consumption. A very im­ portant factor where constant low level operations require relatively low fuel consumption.

The Buffalo can carry a payload more than twice that of the Caribou, has roughly double the range and is around 70 knots faster at Ion range cruise. Buffalo can also operate in totally adverse terrain and airstrip conditions as is evidenced by its CBR (California Bearing Ratio) rating of 3. 5 or less. The CBR is a widely used index of the soil strength required for various vehicles. Natural soil surfaces are rapidly damaged by aircraft designed to use paved runways. For ex­ ample, a field with a CBR of 8. 0 may be used fo,rseveral hun­ dred landing and takeoff cycles, or coverages by an aircraft des’igned for the purpose, but will require repairs or become unusable after relatively few coverages by a conventional transport. The graph accompanying this article shows mo. re conclusively the actual CBR comparison between a C130 and· the DHC5D.

Apart from troop transport and resupply missions the RAAF could well utilise their projected fleet of 24 to 30 air­ craft in the maritime surveillance role thanks to the long en­ durance (10 hours with the addition of a cabin mounted bag tank) of the Buffalo. Hawker DeHavilland have already tabled their suggestions on this aspect of Buffalo operations to DOD and indeed it would seem a more feasible idea to utilise exist­ ing equipment in this role rather than purchase an additional type of aircraft (F27 Maritime, Coastguarder, Defender, etc) which may not really be required.

So much for the Buffalo.

A similar aircraft in concept to the DeHavilland Canada product is the Italian Aeritalia G222.

First flown in 1970, the G222 became operational with the Italian air force in 1976 and has been ordered in limited numbers by Dubai and Argentina. Rather similar in physical size to the Buffalo, the G222 is powered by slightly more powerful versions of the GE T64, carries a little more effective payload and it does this with a much expanded range capability.

On the debit side, the G222 does not have the soft field STOL capabilities of the DHCSD or quite the AIP involvement that DeHavilland can offer. On the political side many people now feel it risky in the long term to purchase Italian weaponry due to the inevitable conclusion that that country must at some point in the next decade go communist. Whether or not this would affect the RAAF while operating mythical G222s against communist _guerrillas in New Guinea has yet to be determined (thankfully!). Still after the Carl Gustav ex­ perience, I am certain that Australia will be looking closer to her traditional UK/USA sources of supply for future weapon systems.

All this prophesy aside, the G222 is a fine aeroplane and one that deserves close consideration as a future RAAF transport. In standard troop configuration, the G222 can accommodate 44 fully equipped troops or 32 paratroopers. As a cargo transport, the G222 will accept standard pallets of up to 7ft 4 in wide and provision is made for 135 cargo tiedown, which are discharged through two large diameter nozzles situated slightly beyond the open rear ramp.

For a long time there existed only two viable contenders for the Tactical Transport role – the G222 and the DHC5D, with the latter being well ahead in favouritism. Then in came Lockheed with a potentially exciting concept that may just completely rewrite the Lockheed airlifter order books for the next two decades or so.

Obviously grasping the proud fact that there are more than 1500 C130 Hercules operated by the air arms of some 42 countries, Lockheed thought it about time (after 20 years of volume production) that they investigated the market capabilities for a mini-Hercules. The result is the L400 and it has resulted in the proverbial cat being put among the HdH pigeons! The L400 is still a projected programme as Lockhee_d needs the basic assurance of at least 30 sales before com-points and a 3305Ib capacity cargo hoist. Like all modern day airlifters the G222 possesses excellent RORO capabilities via its rear loading ramp.

Aeritalia aren’t resting on their laurels though and have quite a few derivatives planned for the future. Inevitably there is a maritime surveillance aircraft and of equal interest is the water-bomber version now in operation with_the Italian air force. Known as SAMA, this palletised unit is designed by the Food Machinery Corporation of California, the dispersal kit includes a 1386 imp gallon water tank, the contents ofmencing initial prototype development. In the meantime, though, extensive wind tunnel testing has been undertaken and the entire preliminary design has been thoroughly es­ tablished – much of it being a straight copy of the totally proven C130 structure.

Basically, the L400 will be able to carry a 22,500Ib payload over a 500 mile range operating from airfields in the 3500 category. This is an advantage of around 4000Ib in payload over the Buffalo which still completes rotation 700ft shorter than the L400. Where the L400 really looks good, at least to air arms already employing its bigger brother, is in the fact that almost all internal systems are identical to the Hercules including the overall internal dimensions of the aircraft. Hence there is no need for duplicated maintenance and support equipment or for that matter the need for extensive retraining of ground personnel, etc. This in-built commonality represents a real advantage for Lockheed wherever they present L400 proposals to established Hercules operators.

Cost wise the L400 is stated to cost in the region of 75 per cent of its bigger brother, which would indicate around $US6m an aircraft in 1978 dollars. Despite a higner unir cost than either the DHCSD or G222, there is a considerable saving in long term operation due to, firstly, the commonality of support equipment and less need for airc. rew flying time in the C130 aircraft. Secondly much of the RAAF C130 operations are by nature underutilised both in range poten­ ,tial and load capacity. The L400, being of same internal dimensions, could perform many flights now made by the more costly C130 in a far more economical manner. Over a period of 20 years, this teaming of aircraft types could presentThe proposed L400 is powered by two Allison 501-D22D turboprops developfng 4910esiip for TO anJ a maximum continuous power rating of 4365eshp. Propellors are Hamilton Standard fully . reversible units of some 14ft 6in longer than the standard C130 units. Standard L400 crew is two persons, half that of the C130, while the L400 can carry more than double the number of fully equipped (92) troops as either of its competitors.

Lockheed are offering a number of advanced avionics/electronics kits to suit individual requirements in­ cluding that of maritime surveillance. However, as we stated before, this is still technically a paper aeroplane and develop­ ment go-ahead may not be given till as late as mid-1978 in view of global economic stagnation. If the L4UO is a goer, though, it will be an instant serious competitor for DeHavilland and for all the same reasons.

TAC Transport

The Contenders