Rotary Wing Fleet : A Formidable Operational Asset
The history of Rotary Wing Aviation can be said to have commenced in 1936 when the German Folcke-Wulf Fw 61 became the first practical functional helicopter. It is however the Sikorsky R-4 that became the first helicopter to enter full scale production in 1942.
A single main rotor with anti-torque tail rotor is the most common design. However, Tandem rotor helicopters are also in widespread use and allow greater payload capacity. There are also coaxial-rotors and tiltrotor craft and quadcopters are being used for specialized applications such as unmanned drones.
Helicopters have a clear advantage over the fixed wing aircraft in terms of vertical take-off and landing and ability to hover on the spot, and fly backwards and laterally. They could thus operate from congested or isolated areas. Military helicopters are a key operational asset of any modern Armed Force. Modern helicopters are modular in construction and could be quickly configured into armed; transport; ambulance; rescue or anti-shipping warfare roles thus retain flexibility and save costs.
Today, helicopter roles include transportation of people and cargo, military operations, construction, fire-fighting, search and rescue, tourism, medical transport, law enforcement, agriculture, news and media, and aerial observation, among others. Military transport helicopters are used to transport personnel (troops) and cargo in support of military operations. The larger helicopters like Mil Mi-26 can carry 90 troops or 20,000 kg cargo. Boeing CH-47 Chinook can carry 55 troops or 10,886 Kg cargo. They can also carry large under-slung loads. The personnel and cargo can be picked and dropped at unprepared locations. These helicopters are also used for air assault to move assault force from assembly areas to landing zones (LZ) or drop zones (DZ). The helicopters can continually resupply the force or support leap-frog to next locations.
Attack helicopters are designed with narrow fuselage, tandem seating, and high external visibility and have high manoeuvrability. They take on anti-tank, anti-helicopter, anti-UAV, and close air support roles. Guns and important sensors are chin mounted. Rockets and missiles are carried on stub wings. They are normally equipped with short range radar and Forward Looking Infra-Red (FLIR) sensors. They have laser rangefinders and laser target designators. Many gunships can also carry a few troops.
Observation helicopters are used to monitor the battle in Tactical Battle Area (TBA). The observation could be visual by the aircrew, or using an optical sensor like low-light level television (LLTV) or FLIR camera. These helicopters also assist targeting by artillery fire and airstrikes. They can also do laser illumination for laser-guided bombs (LGBs) and other weapons fired by mother or other armed aircraft.
Maritime helicopters basic tasks are for observation duties; inter-ship movements; and also for recovery of pilots who may have ditched, or sailors fallen overboard. Special tasks include anti-submarine warfare role and dropping air-launched torpedoes and depth chargers. Integral dunking sonar, radar and magnetic anomaly detectors help better response to submarine threats. Multi-role helicopters nowadays operate nearly autonomously in the ASW, anti-shipping, transport, SAR and reconnaissance roles.
Helicopters form an important anti-submarine strength of carrier aircraft. Shore based helicopters are also used for anti-submarine missions to protect against hostile submarines loitering outside military ports and harbours. Search and Rescue (SAR) and medical evacuation remain key roles for helicopters. A similar mission from behind enemy lines would be a Combat SAR (CSAR). Such helicopters have radio or optical homing devices and also lift winch capability.
A Typical Attack Profile
Attack helicopter is a formidable weapon platform to take-on tanks on the ground from reasonable stand-off ranges using anti-tank guided missiles (ATGM). The attack is often preceded by a lightly armed scout helicopter flying a nap-of-the-earth approach to locate the enemy armoured columns. Newer scout helicopters include laser designators to guide missiles fired from the attack helicopters. After finding a target, the scout helicopter directs the attack helicopter for missile firing. The attack helicopter only has to rise from cover briefly to fire their missiles before returning to a concealed location.
Many modern helicopters like Mi-28N, Kamov Ka-52 and Apache AH-64D Apache Longbow have sensors for standalone operations. The American AGM-114 Hellfire and Russian 3M11 Falanga missiles are the current state-of-the-art weapons. For better combat endurance forward arming and refuel points (FARP) at pre-arranged locations are created to re-arm and refuel, often with their engines running and the rotors still turning, and to quickly return for next attack. Attack helicopters are also used for counter-insurgency (COIN) missions to deter the insurgent forces from operating, and/or to capture or kill the insurgents. Helicopters bring in surprise and tactical flexibility and can engage targets quickly. They have been very effective in operations in Afghanistan and Iraq.
Helicopters in Special Ops
All major Armed Forces of the world have special operations forces (SF) and aircraft. Helicopters have a great role in special operations. FLIR, night vision capability, all-weather weapon aiming sights, and self-protection systems to defend from aerial/ground fired weapons are crucial to special operation helicopters.
Special missions require precision application of firepower, infiltration, exfiltration, and resupply. While various utility and armed helicopters have been used for such missions, CV-22 Osprey tilt-rotor is a dedicated Special Operations aircraft. Some of the other special missions include Combat Search and Rescue (CSAR), reconnaissance, psychological operations, radar assault/bursting etc. The Bell-Boeing MV-22 Tilt-Rotor has had good combat exposure in Afghanistan and On 2 May 2011, following Operation Neptune’s Spear, MV-22 was used to fly the body of Osama bin Laden to aircraft carrier Carl Vinson for his sea burial. Russian Heli-borne SFs transported by Mil Mi-17 helicopters were used extensively during the Soviet war in Afghanistan including storming of the palace and killing of President Hafizulla Amin and his guards. The Boeing CH-47 Chinook helicopters have been used extensively in Iraq and Afghanistan for Heli-borne assault missions and battlefield resupply.
For Operational survivability military helicopters are rugged and more manoeuvrable and have some amount of armoured protection. The most protective plating is around the cockpit, engines, transmission and fuel tanks. Kevlar armour is light and strong. Redundancy of systems also improves survivability. Two-engine helicopters are preferred. These helicopters normally have a self-protection suit with electronic countermeasures, and chaff and flare dispensers.
Humanitarian Assistance and Disaster Relief (HADR)
The largest single non-combat helicopter operation in history was the disaster management operation following the 1986 Chernobyl nuclear disaster involving airdrops. Use of helicopters to control wild fires using Heli-buckets is routine nowadays. The helicopter fleets are engaged round-the-year for HADR missions. In India, parts of J&K are cut-off every winter during heavy snow-fall. IAF sets up
air-bridge to move stranded men and materials. Similarly they are used during cyclones and floods. Helicopters also rescue skiers during landslides. IAF’s role in the relatively inaccessible mountainous terrain, as also was the case during Uttarakhand floods of 2013, is crucial and time-critical. IAF was the first to reach Nepal during the recent massive earthquake and helicopters went village hopping pulling-out survivors. Armed Forces are proud of the fact that invariably they are the ‘first to enter and the last to leave’.
Helicopters in Indian Sub-Continent
The major manufacturers of helicopters in the world are Boeing, Bell Helicopters and Sikorsky in USA, AugustaWestland and Eurocopter in Europe, Mil and Kamov in Russia, and Changhe Aircraft Industries Corporation of China. China’s People’s Liberation Army Air Force (PLAAF) operates Changhe Z-8, Z-9, and Z-11 which were supported by Eurocopter and are built under license. They also have medium lift Z-18, Z-19, Z-20, Mi-8/Mi-17, and Eurocopter AS332 Super Puma helicopters. WZ-10 and the smaller Z-19 attack helicopters are under advanced stage of development.
The HAL Chetak and Cheetah are light utility helicopters. HAL ALH Dhruv and Dhruv-WSI; the weaponised version called ‘Rudra’ have entered the Indian Armed Forces in significant numbers. Over 240 have been built till date. The same basic platform is being used to develop the Light Combat Helicopter (LCH) and Light Utility Helicopter (LUH). HAL LUH flew its first flight in September 2016 but could take another 3-4 years to induct. These aircraft have a NVG compatible cockpit.
IAF has a significant fleet of Mil Mi-8, Mi-17, Mi-17 1V and Mi-17V 5 medium lift utility helicopters and three Mil Mi-26 heavy lift helicopters. There are two squadrons of Mil-Mi-25/35 attack helicopters. IAF has ordered 22 Boeing AH-64E Apache attack Helicopters. These are armed with a 30 mm gun and have four hard points mounted on stub-wing pylons, typically carrying a mixture of AGM-114 Hellfire missiles and Hydra 70 rocket pods. Longbows also have a station on each wingtip for an AIM-92 ATAS twin missile pack. These will join IAF by 2019.
An order has been placed for 68 HAL Light Combat Helicopters (LCH) and 35 HAL Rudra attack Helicopters and 15 CH-47F Chinook heavy lift helicopters that have been ordered have primary roles of troop movement, assault missions, artillery emplacement, battlefield resupply and heavy casualty evacuation. The first aircraft will arrive in 2019.
The existing fleet will be augmented / replaced with 50 Mi-17V-5s. The Indian Army has a sizeable helicopter fleet mainly consisting of Dhruv variants, Chetak and Cheetah. They await Kamov Ka 226 T, 200 of which are planned to be produced in India jointly with HAL. They have also placed orders for 114 LCH. Indian Navy operates the Kamov-31 for airborne early warning, Sea King, Ka-25, Ka-28 and Dhruv in an anti-submarine role. So are Westland Sea King and Sikorsky Sea King. Seventeen of the Sea King helicopters will be upgraded with night capability and integration of two anti-ship missiles and new radar.
The existing fleet of Westland Sea King helicopters would be replaced by 16 Multi-role S-70B Seahawk helicopters. Indian Navy will eventually replace all Chetaks with 120 Dhruv helicopters. The naval variant is fitted with the Super Vision-2000 maritime radar with 200 km range, dunking sonar, torpedoes, depth charges etc. Later they may get missiles for anti-ship roles. Indian Navy also has interest in the armed Rudra and plans to induct 20. Navy will also get the Ka 226T LUH. Pakistan operates 45 Mi-17 helicopters, a few which has been transferred by China. They also have around 100 Aerospatiale Alouette III light helicopters, a few of which have been assembled locally.
IAF Helicopter Ops
IAF Mi-4 helicopters were used for Heli-borne ops in the 1971 Bangladesh war. Siachen Glacier is the highest battlefield in the world with posts at heights up to 23,000 feet. IAF’s Mi-8/17 and Cheetah helicopters airlifted hundreds of Indian troops to Siachen in 1984, and till date continue to support them. In 1987, for Op Pawan of Indian Peace Keeping Force (IPKF) in Sri Lanka, about 70,000 sorties were flown by the IAF’s transport and helicopter force without a single aircraft lost or mission aborted. Mi-8s supported the ground forces and also provided air transportation to the Sri Lankan civil administration. Mi-25s provided suppressive fire against militant strong points and to interdict coastal and clandestine riverine traffic.
In the 1999 Kargil Conflict, IAF provided close air support using helicopters. While on an offensive sortie, a Mi-17 was shot down by three Stinger missiles and lost its entire crew of four. Helicopters thereafter were used only in operational logistic and communication missions. IAF has regularly contributed helicopters to UN Peace keeping force.
Helicopters in Counter Insurgency Role
Helicopter’s versatility is a big asset for use in counter insurgency role. IAF’s helicopters are deployed in Op ‘Triveni’ against Maoist insurgency. Day and night ops include aerial surveillance, infiltration/exfiltration of ground forces, maintaining crucial operational supply line, ambulance operations and casualty evacuation. The helicopters are armed for self-defence and have clearance to fire in case the helicopter is attacked. In J&K Indian Army uses helicopters for surveillance of possible infiltration points, while IAF supports quick reinforcements. Helicopters can be used to pursue militants and help ground forces to join up with them. They are often mounted with search lights and thermal sensors for night pursuits. It merits mention however that the slow moving helicopter faces risk from ground fire, especially Man Portable short range ground-to-air missiles.
Future Combat Helicopter Systems
US Army is working on Future Vertical Lift program - 2030. Survivability has emerged as a key issue for upgrades and new designs, and would include ballistic protection for crew and fuel tanks, crashworthy seats and missile warning systems. Also situational awareness which has caused more crashes than enemy action needs improvement. They are looking at improved engine power for the AH-64 Apache. The Black Hawk is the most popular military helicopter around the world, with 3,600 flying. US Army officials have set a goal of 50 percent better engine performance while using 25 percent less fuel for the Apache and Black Hawk.
Ground-based man-portable air defence systems (MANPADS) continue to be a threat to helicopters. Missile warning and countermeasure responses are needed in addition to protection against non-guided systems such as rocket-propelled grenades (RPGs) and small-arms fire. The electromagnetic EL/L8265 warning and locating system of Israeli Aircraft Industries (IAI) gives the pilot the exact location of the threat. Designed to operate in dense and complex radar environments, it requires minimal pilot intervention. The Common Infrared Countermeasures (CICM) will help battle heat-seeking missiles. Efforts are also on to improve AH-64E Apache attack helicopter’s advanced laser-targeting capabilities. Upgrades will allow Apache pilots to see high-resolution, near-infrared and colour imagery on cockpit displays. New laser-pointer markers and multi-marker lasers with eye-safe lasing capability will come next. Newer Chinooks have directional infrared countermeasures and advanced cockpit instrumentation.
The Helicopter Active Protection System (HAPS), with four sensors to ensure 360-degree threat coverage, will not only identify incoming threats for helicopter operators but also launch and guide a kill vehicle to destroy the RPG or threat through electro-optical sensor technology. The kill vehicle will fit within the envelope of a standard flare and chaff launch tube.
Helicopters will continue to play a critical operational role in years to come.