Military helicopter

Source: Wikipedia, the free encyclopedia.
A UH-60 Black Hawk operated by the Royal Jordanian Air Force

A military helicopter is a

transport helicopters can be modified or converted to perform other missions such as combat search and rescue (CSAR), medical evacuation (MEDEVAC), airborne command post, or even armed with weapons for attacking ground targets. Specialized military helicopters are intended to conduct specific missions. Examples of specialized military helicopters are attack helicopters, observation helicopters and anti-submarine warfare
(ASW) helicopters.

Types and roles

Military helicopters play an integral part in the sea, land and air operations of modern militaries. Generally manufacturers will develop airframes in different weight/size classes which can be adapted to different roles through the installation of mission specific equipment. To minimise development costs the basic airframes can be stretched and shortened, be updated with new engines and electronics and have the entire mechanical and flight systems mated to new fuselages to create new aircraft. For example, the Bell UH-1 Iroquois (known as the "Huey") has given rise to a number of derivatives through stretching and re-engining, including the Bell AH-1.

Modern helicopters have introduced modular systems which allow the same airframe to be configured for different roles, for example the Augusta Westland AW101 "Merlin" in Royal Navy service can be rapidly configured for ASW or transport missions in hours. To at the same time retain flexibility and limit costs, it is possible to fit an airframe for but not with a system, for example in the US Army's Boeing AH-64D Apache variants are all fitted to be able to take the Longbow radar system, but not enough sets have been bought to equip the whole force. The systems can be fitted to only those airframes that need it, or when finances allow the purchase of enough units.

Equipment

Most military helicopters are

Blackhawk
family of helicopters uses two engines and can continue to fly on only one (under certain conditions), the engines are separated by the transmission and placed so that if attacked from any one flank, the engine on that flank acts to protect the transmission and the engine on the other side from damage.

Aviation electronics, or

command posts
.

Armour, fire suppression, dynamic and electronics systems enhancements are invisible to casual inspection; as a cost-cutting measure some nations and services have been tempted to use what are essentially commercial helicopters for military purposes. For example, it has been reported that China is carrying out a rapid enlargement of its assault helicopter regiments with the civilian version of the Russian

Group Armies
, allowing a widespread buildup of experience in helicopter operations.

Attack

A Z-10 of the People's Liberation Army Ground Aviation

anti-tank and close air support roles. The first of the modern attack helicopters was the Vietnam era Bell AH-1 Cobra, which pioneered the now classic format of pilot and weapons officer seated in tandem in a narrow fuselage, chin mounted guns, and rockets and missiles mounted on stub wings. To enable them to find and identify their targets, some modern attack helicopters are equipped with very capable sensors[2] such as a millimeter wave
radar system.

Transport

An Mi-26 operated by the Russian Air Force

Transport helicopters are used for transporting personnel (troops) and cargo in support of military operations. In larger militaries, these helicopters are often purpose-built for military operations, but commercially available aircraft are also used. The benefit of using helicopters for these operations is that personnel and cargo can be moved to and from locations without requiring a runway for takeoffs and landings. Cargo is carried either internally, or externally by slung load where the load is suspended from an attachment point underneath the aircraft. Personnel are primarily loaded and unloaded while the helicopter is on the ground. However, when the terrain restricts even helicopters from landing, personnel may also be picked up and dropped off using specialized devices, such as rescue hoists or special rope lines, while the aircraft hovers overhead.

Air assault is a military strategy that relies heavily on the use of transport helicopters. An air assault involves a customized assault force that is assembled on the pick-up zone and staged for sequential transport to a landing zone (LZ). The idea is to use the helicopters to transport and land a large number of troops and equipment in a relatively short amount of time, in order to assault and overwhelm an objective near the LZ. The advantage of air assault over an airborne assault is the ability of the helicopters to continually resupply the force during the operation, as well as to transport the personnel and equipment to their previous location, or a follow-on location if the mission dictates.

Observation

An Aérospatiale Gazelle operated by the French Army Light Aviation

The first

forward looking infrared cameras. Often, these are mounted in a stabilised mount along with multi-function lasers capable of acting as laser rangefinder and targeting designators for weapons systems.[3]

By nature of the mission, the observation helicopter's primary weapons are its sensor suite and communications equipment. Early observation helicopters were effective at calling for artillery fire and airstrikes. With modern sensor suites, they are also able to provide terminal guidance to anti-tank guided weapons, laser-guided bombs and other missiles and munitions fired by other armed aircraft.[4][5] Observation helicopters may also be armed with combinations of gun and rocket pods and sometimes anti-tank guided missiles or air-to-air missiles, but in smaller quantities than larger attack helicopters.[6] Primarily, these weapons were intended for the counter-reconnaissance fight—to eliminate an enemy's reconnaissance assets—but they can also be used to provide limited direct fire support or close air support.

Maritime

An AH-1 SuperCobra (left) and UH-1Y Venom (right) operated by the United States Marine Corps

Among the first practical uses of helicopters when the

observation aircraft. Another niche within the capability of the early helicopters was as plane guard - tasked with the recovery of pilots who had ditched near an aircraft carrier
.

As helicopter technology matured with increased payload and endurance, anti-submarine warfare (ASW) was added to the helicopter's repertoire. Initially, helicopters operated as weapons delivery systems, attacking with air-launched torpedoes and depth charges based on information provided by its parent and other warships. In the 1960s, the development of the turboshaft engine and transistor technology changed the face of maritime helicopter aviation. The turboshaft engine allowed smaller helicopters, such as the Westland Wasp, to operate from smaller vessels than their reciprocating engine predecessors. The introduction of transistors allowed helicopters, such as the Sikorsky SH-3 Sea King, to be equipped with integral dunking sonar, radar and magnetic anomaly detection equipment. The result was an aircraft able to more quickly respond to submarine threats to the fleet without waiting for directions from fleet vessels.

Today, maritime helicopters such as the Sikorksy SH-60 Seahawk and the Westland Lynx are designed to be operated from frigates, destroyers and similar size vessels. The desire to carry and operate two helicopters from frigate- and destroyer-sized vessels has affected the maximum size of the helicopters and the minimum size of the ships. Increasing miniaturisation of electronics, better engines and modern weapons now allow even the modern, destroyer-based, multi-role helicopter to operate nearly autonomously in the ASW, anti-shipping, transport, SAR and reconnaissance roles.

Medium- and large-sized helicopters are operated from carriers and land bases. In the British, Spanish, and Italian navies, the larger helicopters form the main anti-submarine strength of carrier air wings. When operating from shore bases, the helicopters are used as anti-submarine pickets to protect against hostile submarines loitering outside military ports and harbours; their endurance and payload providing advantages over smaller helicopters.

Soviet maritime helicopters, operating from its cruisers, had the additional role of guidance of the cruisers' long range anti-shipping missiles.

Maritime helicopters are navalised aircraft for operation from ships. This includes enhanced protection against salt water corrosion, protection against ingestion of water, and provision for forced ditching at sea.

Multi-mission and rescue

military dog
being lifted into a rescue-equipped UH-60 Black Hawk

As helicopters came into military service, they were quickly pressed into service for

USAF acquired Sikorsky S-61R (Jolly Green Giant) and Sikorsky CH-53 Sea Stallion (Super Jolly Green Giant) helicopters for the Combat search and rescue (CSAR) mission.[7]

Training

Some services use a version of their operational helicopters, usually in the light class, for pilot training. For example, the British have used the Aérospatiale Gazelle both in operations and as a trainer. Some services also have an ab initio phase in training that uses very basic helicopters. The Mexican Navy has acquired a number of the commercially available Robinson R22[8] and R44 helicopters for this purpose.

Utility

A utility helicopter is a multi-purpose helicopter. A utility military helicopter can fill roles such as ground attack, air assault, military logistics, medical evacuation, command and control, and troop transport.[9]

Tactics and operations

While not essential to combat operations, helicopters give a substantial advantage to their operators by being a

force multiplier. To maximise their impact, helicopters are utilised in a combined arms approach.[10]

High intensity warfare

An Aérospatiale Alouette II anti-tank helicopter of the German Army armed with SS.10 missiles

High-intensity warfare is characterized by large arrays of conventional armed forces, including mass formations of

3M11 Falanga missile for firing from the Mil Mi-24
.

An OH-58 and an AH-1 of the Hawaii Air National Guard. Such a combination would have formed hunter-killer team during the Cold War.[7]

In the air, attack helicopters armed with anti-tank missiles, and one or more unarmed, or lightly armed scout helicopters operate in concert. The scout helicopter, flying at low level in a

Kamov Ka-52, and the AH-64D Longbow
, incorporate sensors and command and control systems to relieve the requirement for scout helicopters.

To enhance the combat endurance of these missile-armed helicopters, transport helicopters were used to carry technicians, reloads and fuel to forward locations. Establishing these forward arming and refuel points (FARP) at pre-arranged locations and times allowed armed or attack helicopters to re-arm and refuel, often with their engines running and the rotors still turning, and to quickly return to the front lines.[7]

Low intensity warfare

COIN operation

In counter-insurgency (COIN) warfare, the government force establishes its presence in permanent or temporary military bases from which to mount patrols and convoys. The government forces seek to deter the insurgent forces from operating, and to capture or kill those that do. The operation of forces from fixed bases linked by a fixed network of roads becomes a weakness. Emplaced insurgents and local sympathisers may observe such facilities covertly and gather intelligence on the schedules and routes of patrols and convoys. With this intelligence the insurgents can time their operations to avoid the COIN forces or plan ambushes to engage them, depending on their own tactical situation.

Helicopters return a measure of surprise and tactical flexibility to the COIN commander. Patrols need not start and end in the same place (the main entrance of the local compound), nor do supply convoys need follow the same roads and highways. During the Rhodesian Bush War, the Rhodesian military developed and refined "Fireforce" tactics, using small flights of light helicopters, the helicopters would be equipped as gunships to directly attack insurgents with aerial gunfire and also as either an airborne command/observation post or troop transport. Once contact had been established against enemy guerillas paratroopers would be dropped by a Dakota and act as "beaters" to drive the guerillas into stop groups landed by the helicopters.

During

Iraqi insurgency.[11]

Due to the cost and complexity of training and support requirements, insurgent forces rarely have access to helicopters.

Manufacturers