Ass and Trash haulers

OPERATION DESERT SHIELD in the last quarter of 1990 was a graphic reminder of one of the basic essentials of war; «getting there firstest with the mostest», as Andrew Jackson pithily put it. The tremendously rapid build-up of force halfway across the world, from the country which supplied the majority of it, can be regarded as decisive. In terms of size, speed, and distance, it was unparalleled in the entire history of warfare, and one day, when the definitive history of the Gulf War is written, air logistics will be acknowledged as the foundation of victory.

Once the shooting starts, modem warfare is dependent on three things; speed of reaction, striking power, and combat persistence. Without an effective logistics infrastructure, a field commander will be unable to do much, nor go very far. POL (petrol, oil, lubricants), munitions, rations, spare parts ond even reinforcements will run short very quickly. Without adequate supplies, it is very difficult to exploit a local, let alone a theatre success, or to restore a precarious situation. Nor does this apply only to surface forces. Air operations ore notoriously prodigal of material resources.

Logistics can be defined as the art of producing the right amount of the correct stores in the exact place they are wanted and at the right time. Distances of hundreds, and even thousands of miles are commonplace, and such are the vagaries of war that the places where particular stores are needed are invariably the most inconvenient from the delivery aspect, while speed is always of the essence. Typical transport methods are sea, rail, road and air, each of which has strong points and weaknesses.

Ships can carry large quantities of troops or equipment, and also outsize or ultra-heavy loads, over long distances very economically, but they are comparatively slow, and unless an amphibious operation is planned, totally dependent on convenient seaports, while operations in landlocked countries rule them out entirely. This is not to say that ships are irrelevant in long distance deployments; the sheer volume and mass that they carry sees to that. They provide a valuable backup; strategic air transport provides the ground forces with the Railways can carry lesser amounts over shorter distances far more quickly, provided only that a rail network exists which not only goes in the right direction, but can sustain a high volume of traffic. Like shipping, rail transport is economical, but is vulnerable to disruption by enemy action.

Road transport is far more flexible than either shipping or railways, but being labour and vehicle-intensive, is wasteful of resources and adds to the overall logistics problem. It is slow, and operates on a law of diminishing returns as distances increase, due to the need to constantly supply fuel. Like rail transport, it also depends on the availability of good roads leading in the right direction. It is vulnerable to enemy action, particularly at choke points such as bridges or tunnels, and tends to be self-impeding when the volume of traffic is high.

Air transport is potentially the most flexible method of all, and is by far the fastest, although it is expensive to operate and individual aircraft carry relatively small quantities. Larger aircraft carry heavier loads over longer distances, but in general are restricted to airfields with long runways and good unloading and handling facilities. This normally restricts them to airfields far behind the battlefront which are reasonably secure from enemy air attack. From these rear areas, supplies and reinforcements must be redistributed to forward airfields by smaller tactical transports.

Trash haulers fall into three broad categories, although there is of course a certain amount of overlap. First there is the strategic transport, able to carry bulky or heavy loads over very long distances at high speeds. Secondly there is the smaller tactical transport, able to haul moderate loads over quite respectable distances, albeit at moderate speeds. Finally there is the small short ranged STOL aircraft, able to lift minor loads in and out of the equivalent of a tennis court. In part one, we concentrate on the first category, using an arbitrary distinction of 5,000km (3,1069 miles) range, leaving other categories to be dealt with in part two.

Strategic airlifters operate into an airhead, which is the aviation equivalent of a railway marshalling yard, ond not a blonde bimbo. As this represents a prime target for enemy attack, congestion must be avoided at all costs, with the fewest possible aircraft on the ground at any one time. Arrivals of the strategic birds must therefore be carefully spaced, the best analogy being that of a conveyor belt.

This is not easy, and several factors ore involved. Airfield handling capacity is critical: the rate at which aircraft can be unloaded and turned round. This is aggravated if the cargo is to be sent on to forward airfields by tactical transports. These are invariably much smaller; the rule of thumb is that it takes up to four tactical transports to handle the load of one large strategic airlifter. This adds to the congestion problem. When deployments are made over vast distances, refuelling becomes necessary, in flight or on the ground, and this is another potentially limiting factor on keeping correct spacing between arrivals. Problems in timing also arise when aircraft with different cruising speeds are utilised on the same route. Often these can only be resolved by complicated calculations at the despatching end.

Troop carrying can of course be done by civilian airliners pressed into service, and while some of these have freighter variants, they are in many ways unsuited to military airlift work. Tne loading doors are set in the sides of the fuselage. Not only are these too small to accommodate outsize loads, but they ensure that all cargo has first to be placed in position at the entry point, then manoeuvred into place at right angles. To make things worse, the standard low wing position, adopted so that the main gear can be accommodated within the strong wing carry through structure, means that the cargo bay floor must be set above it, and is therefore fairly high above the ground, typically about 16ft (5m), making the aircraft reliant upon special loading equipment for even quite small items.

Purpose designed military transports have the cargo bay floor set very low. This simplifies the loading of containers and pallets from flat bed trucks, and also allows the incorporation of a rear loading ramp which permits wheeled or tracked cargo to be driven directly on board. This affects the entire aircraft layout. Firstly, the wing must be set high, to give maximum interior headroom. This does have the advantage of keeping the wings clear of wayward ground vehicles, and engines clear of potential FOD hazards, and providing that sufficient safety measures are taken, allows the engines to be kept running during loading and unloading, where a fast turnaround is required.

Secondly, the main gear must be located on the sides of the fuselage, which in turn must be strengthened to accommodate it, the wing carry through structure not being available. This, plus the need to strengthen the floor to carry heavy point loads, and to take heavy tracked vehicles such as tanks, inevitably causes an increase in structure weight when compared with a conventional civilian machine, with a corresponding decrease in potential payload.

Thirdly, the need for a self-operating loading ramp has two effects: the first is that the floor of the cargo bay is reduced in length, although a considerable load can be carried by the ramp in the «up» position; while an upswept underside of the rear fuselage, with a correspondingly high tail position, must be adopted. This is a less efficient aerodynamic shape than that of a conventional airliner, and the added drag must be paid for in terms of reduced range and lower cruising speed.

In order to expedite loading and unloading, most strategic airlifters are equipped with a battery of electrically driven winches, combined with a roller system, and in many cases even have overhead lifting gear. In a few very large aircraft, visor type noses are combined with rear ramps to allow drive-on, drive-off access from both ends at once.

Many larger transports have a ‘kneeling’ capability, to bring the cargo bay floor nearer to the ground at the access point. This is a function of the main gear hydraulics. Main gears on the heavy lifters are invariably multi-wheel types with fat tyres to spread the ground load, and are housed amidships under the fuselage. This gives a narrow track, an advantage where taxiway width is limited. Some Russian aircraft are stated to have tyre pressures which are adjustable in flight to suit conditions at the destination airfield and allow them to taxi over gross even at high weights.

For global deployments, speed is of the essence, and this calls for the use or turbofan engines, which give cruising speeds in excess of 400kt (741 km/hr). There is one major exception, the Antonov An-22 Cock, which is powered by four turboprops driving huge contra-rotating propellers, which give quite a respectable turn of speed. Turboprop aircraft are generally more economical than turbofans, especially at lower altitudes, but they are as a rule slower, and few of them have true strategic reach.

In all strategic airlifters, there is a trade-off between fuel and payload. A strategic airlifter with maximum payload can only use two thirds of its available fuel capacity at takeoff, although if in-flight refuelling is used, range does not suffer. Of course, with most cargo’s, maximum payload weight is rarely achieved. To take on extreme example, a full load of aircraft drop tanks would occupy the entire volume available without even beginning to approach the maximum weight allowance. On the other extreme, a very dense cargo, such as artillery shells, would quickly reach the maximum allowable load while leaving a great deal of volume unused. These discrepancies leave a great deal of scope for ingenuity by the despatching officers.

In the longer ranged Western aircraft, maximum fuel load normally far outweighs maximum payload, although with the exception of the ll-76 Candid, this trend is reversed with Russian machines. It is also reversed in smaller aircraft where long range is not a design requirement.

Antonov An-12 (Hauhong Yun-8) Cub

In many ways Cub can be regarded as the Soviet equivalent of the slightly earlier C-130 Hercules. Slightly smaller, it has a similar layout and flies much the same missions as me American aircraft, carrying a comparable payload over rather shorter distances at generally higher speeds. It has good austere field performance, serves with at least 15 air forces worldwide (the number is hard to check with the emergence of so many new nations following the dissolution of the Soviet Union), and has been used for many other roles than transport. There the similarities end, as the basic design has reached the end of its development potential. Soviet production ceased in 1973. As the reverse engineered Yun-8, low rate production commenced in the People’s Republic of China in 1980, and as at 1992 this continued.

In keeping with standard Soviet practice, Cub A mounts a rear gun position, with two 23mm NR-23 cannon in a remotely controlled barbette in the tail. Unusually, the lower portions of the main loading doors fold inwards, instead of forming a drive-in ramp, as is the more normal practice. While this allows trucks to be unloaded with their beds level with the cargo floor, it also means that vehicular cargos need a detachable ramp for entry and exit.

Cubs served side-by-siae with Western aircraft in the Ethiopian famine relief operation in 1986, when their Russian crews became notorious for high speed taxying, which resulted in at least one ground collision. Cub also serves in the tanker, maritime reconnaissance and electronic warfare roles, for which there are specialised variants. Rapidly being replaced by Candid, less than 200 Cubs remain in Russian service. Users: Afghanistan, Algeria, Czechoslovakia, Egypt, Ethiopia, Guinea Republic, Indio, Iraq, Poland, PRC, Russia, Sri Lanka, Ukraine, Yemen, Yugoslavia.

Antonov An-22 Cock

Named Anteus after a Russian folklore hero, An-22 first flew in February 1965, and until the emergence of the C-5A Galaxy, was the world’s largest transport aircraft. In its day, it held a hatful of international records. Basically the result of matching an airframe to four Kuznetsov NK-12MA turboprops as first used on the Tu-20/95/142 Bear, driving giant four-bladed contra-rotating propellers, Cock could and did take the largest and heaviest loads to destinations around the globe.

The design incorporated an unswept wing of very high aspect ratio, and extremely high loading exceeding that of both Galaxy and Condor On the other hand, span loading is comparatively modest. Huge double slotted trailing edge flaps are used for takeoff, landing, and slow speed flight.

Multiple main gears are housed in fairings to either side of the fuselage, thus leaving the cargo hold unobstructed. The first Russian aircraft to be able to airlift a main battle tank, its floor was of reinforced titanium. A complete SA-4 missile battery could also be carried. The rear loading ramp is augmented by an upward rising door, allowing access for tall loads. This door also carries extensions of internal gantry rails to aid loading. Tyre pressures are reported to be adjustable in flight or on the ground, to suit local conditions.

While no admission has been made of structural problems, the attrition rate is high, with over 15% losses to date, many of them overseas. A Cock ferrying a replacement engine for the An-124 at Farnborough 1988 may have given a partial answer. Seemingly confused as to which runway to land on, the pilot appeared to change his mind very late at low altitude, and actually fishtailed his huge aircraft to realign it, missing the hard surface and touching down on the grass beside the junction of two runways. One hopes this is not standard practice!

Production ceased in 1974, after about 80 aircraft had been built. Only about 45 remain in Russian/Ukrainian service.

Users: Russia, Ukraine.

Antonov An-124 Condor/225 Cossack

First flown in December 1982, Ruslan, to give it its Russian name, was the world’s largest and heaviest aircraft at that time, and has only since been surpassed by its sibling, the gigantic An-225 Mriya, in December 1988.

Over the first few years of its operational life, Condor set no less than 21 international world records, including a distance of 10,874nm (20,150km) nonstop in May 1987 in just 25 1/2 hours with the aid of inflight refuelling. Its field length requirements are remarkably modest for such a huge aircraft, with a landing roll at maximum weight of just

2,625ft (800m). The 24-wheel main gear provides low flotation and is steerable, making rough field operations possible.

Ramp access is available from both rear and front, where a visor nose lifts up, with the break just ahead of the cockpit, access to which is by way of a daunting vertical ladder. The cavernous hold, floored with titanium, can hold two T-74 (which NATO insists on calling T-80) main battle tanks, a complete SS-20 Saber IRBM system, up to 30 wheeled vehicles, or eight helicopters.

The An-225 Mriya, NATO reporting name Cossack, was developed from Condor to carry heavy outsize components externally, including Buran, the Russian space shuttle. Wing span was extended by nearly 50ft (15m); length by roughly the same amount, height actually reduced as the single fin and rudder assembly was replaced by two vertical tail surfaces; while maximum takeoff weight increased by a massive 195 tonnes.

To cope with the extra weight and drag, two more Lotarev turbofans were fitted for a total of six. At Le Bourget in 1989, carrying Buran, it amazed watchers by taxying across the grass in a convincing demonstration of ‘go anywhere’.

About 24 Condors are currently in Russian service, and the type contributed to the Gulf War logistics buildup.

User: Russia.

Ilyushin II-76MD Candid

First flown on March 25, 1971, Candid was designed to replace the ubiquitous An-12 Cub, the specification being to transport a 40 tonne payload 2,698nm (5,000km) in under six hours. It therefore had to be much faster than its predecessor; equally able to operate from basic airstrips in difficult weather conditions, while being simpler to service than the earlier aircraft.

The speed requirement demanded turbofan engines, and four Soloviev D30KPs were slung under the wings in pods; a first for a Soviet transport. These were raked steeply forward to keep them well clear of FOD flung up by the nosewheels. The wings were liberally equipped with high lift devices to improve short field performance. Slats occupied nearly all the leading edge, while triple slotted flaps took up the entire trailing edge inboard of the ailerons.

The single leg nose gear and quadruple leg main gears each had four wheels abreast for a total of 20. Typically Russian low pressure tyres were used to meet flotation requirements; the pressures of which could be varied in flight between 36 and 72lb/sq in (2.5 and 5 bar). Not only was this suitable for the more outlandish Siberian airfields, but it allowed supplies to be ferried to aligned nations, often in the Third

World, whose facilities were primitive.

An auxiliary power unit which is used for engine starting without recourse to external aid, keeps the systems running during the turnaround, and provides power for the two internal gantries used for cargo handling. Conversion for troop carrying is rapid, consisting of passenger modules lifted into the cargo bay.

Military Candids retain a rear gun position, with two twin barrel 23mm NR-23 remotely operated cannon, although this is omitted on civilian machines. About 450 Candids are in Russian/Ukrainian service and possibly other countries of the former Soviet Union, and the type has also been modified into Midas (tanker) and Mainstay (AWACS) variants.

Users: Algeria, India, Iraq, Libya, Russia, Syria, Ukraine.

Lockheed C-141B Starlifter

Designed to provide global range capability at jet speeds for the USAF’s Military Airlift Command, the C-l 41A prototype first flew on December 17, 1963. Development was rapid, and it entered squadron service just sixteen months later, in April 1965. Powered by four TF33-P-7 turbofans with thrust reversers for short landings, the Starlifter featured clamshell rear doors with a retractable ramp.

Its range enabled it to fly nonstop from California to Japan, and it was soon on active service, ferrying men and material across the Pacific to Vietnam. One shortcoming quickly became apparent. The cross-section of the cargo hold was just 10ft 3in (3.12m) wide and 9ft lin (2.77m) high, almost identical to that of the C-l 30 Hercules, which was too small for many loads, and also taxed the ingenuity of the loadmasters to get the C-l41 anywhere near its design maximum payload weight. Often it flew with all volumetric capacity used, but with no more than 37% of maximum weight capacity.

Nothing could be done to increase the cross-section, but to improve capacity, the fuselage was stretched by the insertion of two plugs, one of 13ft 4in (4.06m) ahead of the wing: the other of lOrt (3.05m) immediately behind the wing. A flight refuelling probe was installed, and a wing root fairing to reduce drag, thus increasing cruising speed and fuel economy, was fitted. First flown in March 1977 as the C-l41B 269 remain in service.

Often overshadowed by the larger C-5A Galaxy, the Starlifter gave sterling service during Operation Desert Shield, but is probably best remembered for Operation Homecoming, the repatriation of American PoWs from Hanoi in 1973. Late in 1992, Lockheed proposed a SLEP (Service Life Extension Programme) aimed at increasing the design service life from 45,000 hours to 80,000 hours for the 178 newest airframes, involving major structural improvements and replacements. User: USA.

Lockheed C-5B Galaxy

Arguably the world’s foremost strategic airlifter. Galaxy succeeded Cock as the world’s largest aircraft on its first flight in June 1968, a title held until December 1982 when Antonov’s gigantic Ruslan took to the skies.

The C-5A entered service in time to play a crucial role in the final stages of the Vietnam conflict, supplementing the C-l41 Starlifter. During Gulf War operations in 1990/91, the two USAF airlifters combined to haul roughly 370,000 tonnes of cargo and 160,000 personnel into the Kuwait theatre of operations, with most sorties involving a nonstop flight from the continental USA to Saudi Arabia using inflight refuelling. Even this did not occupy the entire fleet, 10% of C-5s and 20% of C-l 41 s were employed elsewhere.

The original specification called for rough field capability and the main gears were given 28 wheels to meet the high flotation this demanded, but it is now generally admitted that Galaxy needs lots of concrete from which to operate, and is thus restricted to using major airfields.

The lessons of the Starlifter had been well learned. Galaxy was given a two-deck hold, the lower one of which had a cross-section of no less than 19ft (5.79m) wide and 13ft 6in (4.11m) high. This can accommodate virtually any load other than landing craft and heavy cranes. Typical loads consist of two M-1 Abrams tanks, ten Black Hawk helicopters, 16 trucks, or a variety of other bulky loads. An innovation was a visor nose to allow simultaneous loading/unloading at both ends. Normal crew is five, and there is ample room for relief crews to be carried.

Entering service in 1970, a total of 81 C-5As was delivered by 1973 when production ceased. Fatigue was an early problem, and in 1977 a rewinding programme was commenced. Then in 1982 a contract was awarded for a further 50 C-5Bs. This variant featured the new wing, uprated engines, and a beefed up airframe which allowed a 9% increase in maximum takeoff weight, and improved avionics. The first C-5B flew on September 10, 1985, and 125 are currently in service. User: USA.

Lockheed C-130 Hercules

Come war, plague, famine, or earthquake, the Herk will be there, bringing relief from the skies, whether it be ammunition for the beleaguered or food for the starving. When, on August 23 1954, the prototype first flew, no-one could have predicted that the design was so right that the number of variants would become legion, with new ones appearing nearly 40 years on.

A combination of payload/range capability, docile handling, versatility, short field performance and ruggedness has been the key to its success. The C-l 30 has sold around the world on sheer merit, while many proposed successors have come and gone. It has served in conflicts around the world, and attained a legendary reputation.

Current transport variants are the C-130H and the C130H-30, a stretched version which is 15ft (4.57m) longer, and which can carry 128 troops or 92 paras. It serves in the tanker, EW, MR, special forces, and gunship roles, and has even been used as an ad hoc bomber. About 1,100 military transport versions are currently in service.

Users: Algeria, Argentina, Australia, Belgium, Bolivia, Brazil, Cameroon, Canada, Chad, Chile, Colombia, Denmark, Ecuador, Egypt, France, Gabon, Greece, Honduras, Indonesia, Iran, Israel, Italy, Japan, Jordan, Kuwait, Libya, Malaysia, Mexico, Morocco, New Zealand, Niger, Nigeria, Norway, Oman, Pakistan, Peru, Philippines, Portugal, Saudi Arabia, Singapore, South Africa, South Korea, Spain, Sudan, Sweden, Taiwan, Thailand, Tunisia, Turkey, UAE, UK, USA, Venezuela, Vietnam, Yemen, Zaire.

McDonnell Douglas C-17A

The main failing of Galaxy and Starlifter is that they can only operate from major airfields, and therefore their cargo must be transported onwards by other means. The C-17A is an attempt to overcome this restriction. In the entire NATO area, for every airfield that can take Galaxy, there are six that can handle the C-17A, while in the world at large the ratio becomes one to eleven. This is a measure of the importance of the C-17A.

Air refuellable, the C-17A is intended to carry heavy and bulky items, such as tanks and APCs, at high speeds over very long distances, directly into forward airfields. It can also air drop tanks, guns and APCs from medium or low levels, very close to where they are needed.

First flown on September 15,1991, the C-17A is currently undergoing flight trials. Its wing span has been held down to ease ground manoeuvring in congested areas, while small vertical winglets on the wing tips reduce vortex drag and increase range. Everything possible has been done to give the manoeuvrability necessary to allow it to make steep turning descents and climb outs. Blown flaps and FBW controls, combined with a glass cockpit are just part of the story. Propulsive lift technology developed for the cancelled YC-15 has been used extensively.

Nor has ground manoeuvrability been neglected. The main gear is of narrow track, and taxiways 50ft (15m) wide present no problems, while a three point turn can be carried out on a runway just 90ft (27m) wide without difficulty. Reverse thrust, which can also be used in flight, shortens the landing run, and can be used to allow the C-17A to reverse up a two degree slope with a full payload, while carrying fuel for the return trip. The value of this is to allow the aircraft to back up to the extreme end of the runway prior to takeoff, so that every inch of concrete is available.

Normal crew consist of two men, plus a loadmaster. Cargo access is via a rear ramp, and possible loads include three M-1 tanks or AH-64 Apache helicopters, or six heavy trucks. Current requirements are for 125 aircraft, but revised thinking about global defence needs may well lead to more in due course.

User: USA.

Antonov An-70T

While the 11-76 was designed as a replacement for the An-12, it was a bit too much upmarket, and not as economical as its predecessor. A more recent proposal is Antonov’s An-70T, revealed to the West in 1992. This is a widebody transport, with a cargo hold 13ft 1 1/2 in (4m) wide, 13ft 5 1/2 in(4.10m) high, and 61ft (18.6m) long excluding the ramp.

Powered by four D-27 turboprops each driving contra-rotating propellors, the An-70T has a relatively small wing area and high wing loading for economical high altitude cruise, with a battery of nigh lift devices on both leading and trailing edges for short field performance. State of the art avionics and automated systems are fitted, and service life is projected as 20,000 flights, 45,000 flight hours, and 25 years.

The baseline payload is 25 tonnes, and an additional five tonnes can be carried on the raised romp. The cargo hold is pressurized and temperature controlled. The An-70T appears to be aimed at the civilian market, but obviously has military applications. Status: Development in the Ukraine.

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