Indian Defence Review

The Lockheed C-5 Galaxy

The Lockheed C-5 Galaxy  is a large military transport aircraft originally designed and built by Lockheed and now maintained and upgraded by its successor, Lockheed Martin. It provides the United States Air Force (USAF) with a heavy inter-continental range strategic airlift capability, one that can carry outsize and oversize loads, including all air-certifiable cargo. The Galaxy has many similarities to its smaller Lockheed C-141 Starlifter predecessor, and the later Boeing C-17 Globemaster III. The C-5 is among the largest military aircraft in the world.

The C-5 is a large high-wing cargo aircraft with a distinctive high T-tail fin (vertical) stabilizer and with four TF39 turbofan engines mounted on pylons beneath wings that are swept 25 degrees. Similar in layout to its smaller predecessor, the C-141 Starlifter, the C-5 has 12 internal wing tanks and is equipped for aerial refuelling. Above the plane-length cargo deck, it provides an upper deck for flight operations and for seating 75 passengers including the embarked loadmaster crew, all who face to the rear of the aircraft during flight. Full-open(able) bay doors at both nose and tail enable “drive-through” loading and unloading of cargo.

Take-off and landing distance requirements for the plane at maximum-load gross weight are 8,300 ft (2,500 m) and 4,900 ft (1,500 m), respectively. Its high flotation main landing gear provides 28 wheels to distribute gross weight on paved or earth surfaces. The rear main landing gear can be steered to make a smaller turning radius; it is rotated 90 degrees after take-off before being retracted. “Kneeling” landing gear permits lowering the aircraft when parked thereby presenting the cargo deck at truck-bed height to facilitate loading and unloading operations.

The C-5 features a Malfunction Detection Analysis and Recording (MADAR) system to identify errors throughout the aircraft. The cargo compartment is 121 ft (37 m) long, 13.5 ft (4.1 m) high, and 19 ft (5.8 m) wide, or just over 31,000 cu ft (880 m3). It can accommodate up to 36 463L master pallets or a mix of palletised cargo and vehicles. The nose and aft cargo-bay doors open the full width and height of the cargo bay to maximise efficient loading of oversized equipment. Full width ramps enable loading double rows of vehicles from either end of the cargo hold.

The Galaxy C-5 is capable of moving nearly every type of military combat equipment including such bulky items as the Army Armoured Vehicle Launched Bridge (AVLB), at 74 short tonnes (67 t), from the United States to any location on the globe and of accommodating up to six Boeing AH-64 Apache helicopters or five Bradley Fighting Vehicles at one time.

The C-17 Globemaster III

The Boeing C-17 Globemaster III is a large military transport aircraft. It was developed for the United States Air Force (USAF) from the 1980s to the early 1990s by McDonnell Douglas. The C-17 carries forward the name of two previous piston-engine military cargo aircraft, the Douglas C-74 Globemaster  and the Douglas C-124 Globemaster II. The C-17 commonly performs strategic airlift missions, transporting troops and cargo throughout the world; additional roles include tactical airlift, medical evacuation and airdrop duties.

The C-17 is 174 ft (53 m) long and has a wingspan of about 170 ft (52 m). It can airlift cargo fairly close to a battle area. The size and weight of US mechanised firepower and equipment have grown in recent decades from increased air mobility requirements, particularly for large or heavy non-palletised outsize cargo.

The C-17 is powered by four Pratt & Whitney F117-PW 100 turbofan engines, which are based on the commercial Pratt and Whitney PW2040 used on the Boeing 757. Each engine is rated at 40,400 lbf (180 kN) of thrust. The engine’s thrust reversers direct engine exhaust air upwards and forward, reducing the chances of foreign object damage by ingestion of runway debris, and providing enough reverse thrust to back the aircraft up on the ground while taxiing. The thrust reversers can also be used in flight at idle-reverse for added drag in maximum-rate descents. In vortex surfing tests performed by C-17s, up to ten per cent fuel savings were reported.

The aircraft requires a crew of three (pilot, co-pilot, and loadmaster) for cargo operations. Cargo is loaded through a large aft ramp that accommodates rolling stock, such as a 69-tonne (63-metric tonne) M1 Abrams Main Battle Tank, other armoured vehicles, trucks, and trailers, along with palletised cargo. The cargo compartment is 88 feet (26.82 m) long by 18 feet (5.49 m) wide by 12 feet 4 inches (3.76 m) high. The cargo floor has rollers for palletised cargo that can be flipped to provide a flat floor suitable for vehicles and other rolling stock.

The maximum payload of the C-17 is 170,900 lb (77,500 kg), and its maximum take-off weight is 585,000 lb (265,350 kg). With a payload of 160,000 lb (72,600 kg) and an initial cruise altitude of 28,000 ft (8,500 m), the C-17 has an unrefuelled range of about 2,400 nautical miles (4,400 km) on the first 71 aircraft, and 2,800 nautical miles (5,200 km) on all subsequent Extended Range models that include a sealed centre wing bay as a fuel tank. Boeing informally calls these aircraft the C-17 ER. The C-17’s cruise speed is about 450 knots (833 km/h) (Mach 0.74). It is designed to air drop 102 paratroopers and their equipment.

The C-17 is designed to operate from runways as short as 3,500 ft (1,064 m) and as narrow as 90 ft (27 m). In addition, the C-17 can operate from unpaved, unimproved runways although with greater chance of damage to the aircraft. The thrust reversers can be used to back the aircraft and reverse direction on narrow taxiways using a three- (or more) point turn. The plane is designed for 20 man-hours of maintenance per flight hour, and a 74 per cent mission availability rate.

The C-17 is 174 feet (53 m) long and has a wingspan of about 170 feet (52 m). It can airlift cargo fairly close to a battle area. The size and weight of US mechanised firepower and equipment have grown in recent decades from increased air mobility requirements, particularly for large or heavy non-palletised outsize cargo.

The purchase of ten C-17 Globemaster III by India makes it the largest international customer. India received ten aircraft by the end of 2014. Speaking at the delivery ceremony of the second C-17 aircraft in July 2013 in Long Beach, former Air Chief Marshal NAK Browne, Chief of the Indian Air Force, said, “Our first C-17 Globemaster III not only signifies a tremendous boost in our strategic airlift capability, but also is poised to form a major component in the IAF’s modernisation drive. Because it was delivered mission-ready, it soon undertook its first strategic mission to our Andaman Nicobar Command at Port Blair. I wish to place on record my appreciation to the US government, the US Air Force and the Boeing team for the timely delivery of the aircraft that makes the IAF the world’s second-largest operator of the C-17 after the US.” Recently, the Indian Air Force deployed two C-17s to airlift its stranded citizens from Yemen under Operation Rahat thus successfully underscoring its strategic reach quite boldly.

The IL 76

The Ilyushin II-76 is a landmark Soviet-era design. Russia’s first four-jet heavy transport, it was conceived and used to fly strategic military cargos into frontline air bases in the most extreme operational conditions. The II-76 prototype made its first flight in 1971. It was intended as a replacement for the An-12. Production commenced in 1974. The basic II-76 (NATO reporting name Candid-A) transport was built purely for military service. It saw extensive service during the Soviet war in Afghanistan. Over 800 of these cargo aircraft were built, as well as a number of specialised versions. The Il-76 is currently in service with Russia, Algeria, Belarus, China, Cuba, India, Iran, Libya, North Korea, Syria and Ukraine.

This aircraft was designed to deliver heavy vehicles and machinery to remote, poorly-serviced airfields. It can operate from short and unpaved runways. The Il-76 can cope with the worst weather conditions experienced in Siberia and Arctic regions.

The tough, dependable airframe spawned many variants – some designed to do the basic transport job even better, and others which serve as indispensable combat support roles. A bewildering array of other specialised variants have been developed for roles including mobile hospital, cosmonaut training and airborne command post, airborne laser platform and fire fighter.

Onboard equipment is intended to execute airlifts and air drop missions by day and at night, in Visual Flight Rules (VFR) and Instrument Flight Rules (IFR) weather conditions, as well as under hostile air defence conditions. The integrated flight control and aiming-navigation system includes a compass system, ground surveillance radar, a central digital computer, automatic monitoring system, automatic flight control system, short-range radio navigation and landing system, IFF transponder, optical/infra-red aiming sight and a ground collision warning system.

IL-76

The IL-76M aircraft  is powered by four D-30KP turbofan engines, mounted on underwing pylons and housed in individual pods secured on the engines. Fuel is held in 12 integral tanks, which are isolated from each other. All fuel tanks are divided into four groups by the number of the engines. An inert gas system is used for protection against explosion.

The Indian Air Force operates a total of seventeen Il 76 MD. Out of these seventeen, three are flown for the Aviation Research Centre (Cabinet Secretariat). The Il 76 MD has, for several years been the mainstay of country’s strategic air lift capabilities. They were used in the Maldives in 1987 and in Sri Lanka during 1987-1990 to great effect. The aircraft also flew pioneering missions to airlift the Bofors Howitzers to Thoise and T-72 tanks to Jaffna and Ladakh. In addition to these other variants flown by IAF are seven Il-78MKI  Aerial Refuellers and three A-50E Phalcon AEW.

The An-124

The design of the AN-124 began in 1971. The aircraft fuselage has a double-deck layout. The cockpit, the relief crew compartment and the troop cabin with 88 seats are on the upper deck. The lower deck is the cargo hold. The flight deck has crew stations arranged in pairs for six crew – the pilot and co-pilot, two flight engineers, the navigator and the communications officer. The loadmaster’s station is located in the lobby deck.

The An-124 aircraft is fitted with a relatively thick (12 per cent) swept-back super-critical wing to give high aerodynamic efficiency and, consequently, a long flight range. The construction includes extruded skin panels on the wing, extruded plates for the centre-section wing panels and monolithic wafer plates for the fuselage panels. The aircraft structural members are made of composites that make up 1,500m² of the surface area.

Multi-leg landing gear and loading equipment ensure self-sufficient operation of the aircraft on prepared concrete runways and on unpaved strips. The landing gear is self-orienting and incorporates a kneeling mechanism, which allows an adjustable fuselage clearance to assist the loading and unloading of self-propelled equipment.

Cargo systems onboard of cargo handling equipment make it possible to load and unload the aircraft without the help of ground facilities. The para-dropping and cargo handling equipment comprises two travelling cranes, two winches, roll gang and tie down equipment. The aircraft is often compared to the US Lockheed Martin C-5 Galaxy. The An-124 has a transportation capability 25 per cent higher than that of the C-5A and ten per cent higher than the C-5B. The two cargo hatches are a distinctive structural feature. The fuselage nose can be hinged upward to open the front cargo hatch and there is a cargo hatch in the rear fuselage.

Avionics systems are quadruple redundant. The onboard equipment provides the capability to execute airlift and para-drop missions by day and at night, in Visual Flight Rules (VFR) and Instrument Flight Rules (IFR) weather conditions. There are 34 computers functioning aboard the aircraft, combined into four main systems – navigation, automatic piloting, remote control and monitoring.

The integrated flight control and aiming-navigation system comprises an autonomous navigation system, altitude and air-speed indicating system, combat formation flight control equipment, short-range radio navigation and landing system, global positioning system, automatic radio compass, ground surveillance radar, forward-looking weather radar, optical and TV sight and IFF equipment.

The new versions are An-124-210 and An-124-100M. An-124-210 will be equipped with a Rolls-Royce RB211-52H-T engine; An-124-100M with series 3 D-18 engines, produced by Progress Design Bureau in Zaporozhe. These engines allow an increase in service range of ten per cent and reduced take-off distance.