Printer Friendly

Attack helicopters for the new Millennium: the switch in defence planning from massed tank battles in central Europe to expeditionary warfare and peacekeeping/enforcement in other continents is moving the emphasis in attack helicopters from dedicated day/night all-weather anti-armour operations to designs that are lighter, less expensive, easier to deploy in fixed-wing transport aircraft and operationally more flexible. (Rotary-wing).

The trend in the market may be toward combining the role of the sensor-plus-weapons platform with either scouting or light/medium transport duties. Meanwhile, the application of precision guidance systems to lightweight rockets has reduced warload requirements in some missions, but helicopter armament may now have to deal with a much wider range of targets, such as mud forts, concrete gun emplacements and boats, rather than just armoured fighting vehicles.

Top of Class

Top-of-the-range attack aircraft, such as the ten-tonne class Boeing AH-64D Apache, the Kamov Ka-50 series and the Mil Mi-28, were designed to deal with multiple armoured targets on the north German plain, a scenario that has no relevance in the new Millennium. The AH-64D, for example, can fly a 3.38-hour sortie with a mission range (presumably US Army-speak for radius of action) of 520 km, carrying 16 AGM-114 Hellfire anti-armour missiles and 1200 rounds of ammunition for its 30 mm ATK M230 Chain Gun. Assuming that the Hellfire has a single-shot kill probability in excess of 50 per cent, this warload radius performance is arguably far in excess of what today's typical operator really needs. It can also be argued that (judging by fixed-wing aircraft in service) most helicopter operators do not require full day/night all-weather capability.

A substantial part of the military rotary-wing market can thus be addressed by a helicopter grossing half as much as the dedicated Cold War tank-busters, and with only a limited adverse weather capability. Such aircraft are considerably less expensive and more easily deployed by air transport, and pose far lower servicing and maintenance workloads as well.

Nevertheless, the Boeing AH-64A has sold well in the Middle East, with Egypt buying 36, Israel 52, Saudi Arabia 12 and the UAE 30. In addition, Kuwait has ordered 16 radar-equipped AH-64Ds and Israel has bought nine, and well-funded services with the older AH-64A may have it upgraded to -64D standard. It also seems likely that, when the stealthy Boeing Sikorsky RAH-66 Comanche enters US Army service, some pre-used AH-64As may be released for international sale at relatively low price.

On a similar theme, the US Army has more than 250 Bell AH-1F Cobras in storage, which could, relatively economically, be given some of the upgrade features of the US Marine Corps' 7.5-tonne AH-1Z. Aside from avionics improvements, the AH-1Z has 1260 kW General Electric T700 engines, a four-blade main rotor, two extra weapon pylons and an increased internal fuel capacity.

The Denel Rooivalk is in a similar weight category, and was likewise based on a great deal of operational experience. It was intended to take off from fields at 5000 ft altitude and at 25 degrees Celcius above the standard atmosphere. Engine air filters are fitted to minimise dust and sand ingestion.

APKWS

The trend to lighter weights will be helped significantly by the advent of laser-homing rockets. The US Army has for several years encouraged the development of guidance kits for 70 mm Hydra 70 projectiles, which are now manufactured by General Dynamics Armament & Technical Products (GDATP).

In February it was announced that GDATP had been contracted to perform the SDD (System Development and Demonstration) phase for the Block 1 unitary warhead version of the US Army's Advanced Precision Kill Weapon Systems (APKWS), which is to enter service in 2005. The company selected BAE Systems of Nashua, New Hampshire to provide the guidance and control module. In essence, the APKWS fills the gap between the unguided ten kg Hydra-70 and the vastly more expensive 50 kg Hellfire laser-guided missile. The US Army plans to buy between 50,000 and 100,000 guided rockets, with a target price of less than $10,000, and a one-metre accuracy from a distance of up to 5.5 km. A 70 mm rocket does not have the armour penetration of a 178 mm Hellfire, or the destructive effect of the blast fragmentation AGM-114M version, but it is effective against a wide range of soft and lightly armoured targets.

The APKWS kit is intended to also be applicable to rocket projectiles such as the Bristol Aerospace CRV7 series and the Forges de Zeebrugge (FZ) 70 mm.

Tiger

The trend to lighter attack helicopters may be illustrated by the 5925 kg Eurocopter Tiger, which first flew in 1991, some 16 years after the YAH-64. Powered by two 958 kW MTU/Turbomeca/ Rolls-Royce MTR390 engines, the Tiger was developed in two basic models for the French and German armies: the dedicated anti-armour HAC/UHT (or the U-Tiger), and the fire support HAP version, which was to have been exported as the HCP. The anti-tank Tiger has a mast-mounted sighting system (removed for air deployment), whereas the fire support model has a roof-mounted sight and chin-mounted Giat 30 mm Type 781 cannon. In view of changing needs, France is considering abandoning the HAC and having all its Tigers built (or upgraded) to a new HAD multi-role standard. The HAD will have uprated engines and an improved roof-mounted sighting system that can guide anti-armour missiles such as the Euromissile Hot-3 and Trigat. The Tiger ARH ordered by Australia is based on the HAP, but with a laser designator for the Hellfire. The Tiger HCE proposed to Spain is based on the Tiger HAD, but also has a Passive Automatic TArget recognition System (Patas).

A129

The five-tonne AgustaWestland A129 International was, from the outset, designed for scout and escort roles. The basic version is that operated by the Italian Army, with a gross weight of 3850 kg. It is powered by two 657 kW Rolls-Royce Gem engines, and can carry eight Raytheon Tow missiles or up to 76 Hydra 70s. The A129 has seen operational service in Somalia, Eritrea, Bosnia and Afghanistan. The export A129 International has 996 kW LHTEC T800-2s and a gross weight of 5100 kg. It also has a five-blade main rotor, a three-barrel GDATP 20 mm M197 cannon in an Otobreda TM197B turret and provisions for Hell-fires and Raytheon Stinger air-to-air missiles. In order to maintain performance under hot/high conditions, the International is also offered with 1185 kW CTS800-50 engines.

China plans to develop a six-tonne, tandem-seat attack helicopter on the basis of the 5.5-tonne CMH (Chinese Medium Helicopter), in which AgustaWestland is providing some assistance to CATIC and AVIC II. Aside from the front and centre fuselage sections, the two designs will be basically the same.

Scout/Utility

A number of light helicopters can be armed with guns and rockets to perform a combined scout and attack role. Belgium's FN Herstal is one of the leaders in developing armament installations for such aircraft.

In view of the number of Eurocopter products discussed below, we should perhaps explain for the benefit of some readers that the company employs a mixture of old (AS-series) and new (EC-series) designations. Under the new system, the first digit (1 or 6) indicates civil or military, the last digit (0 or 5) indicates whether it is single- or twin-engined, and the middle digit is the approximate maximum take-off weight in metric tonnes. Thus, the EC635 is a military twin-engined helicopter in the three-tonne class, but it should be noted that the twelve-tonne, twin-engined Cougar Mk2+ has become the EC725.

The lighter end of the armed utility helicopter spectrum is represented by the Eurocopter Fennec, in the form of the 2250 kg AS550A3/C3 with a single 632 kW Turbomeca Arriel 2B engine, and the 2600 kg AS555AN with two 388 kW Arrius 1As. Both can be armed with a fixed 20 mm Giat 20M621 cannon and 68 mm rocket projectiles, or a roof-mounted HeliTow sighting system and four Tow missiles. In unarmed form (AS550U3/AS555UN), the Fennec can carry up to six passengers.

The name Fennec would also apply to a military version of the new 2400 kg EC130B4 (presumably EC630), which has the single Arriel 2B and can accommodate up to seven passengers. The EC130 represents an extensive redesign, triggered in the late 1990s by competition from the Bell 407 (effectively a LongRanger with a wider cabin and the four-blade main rotor of the OH-58D Kiowa Warrior), MD Helicopters' MD600 and the Agusta A109. It incorporates the Fenestron tail rotor from the EC135 and the canopy from the EC120, allowing a much wider cabin. An interesting feature is that the pilot sits on the left, so that the collective pitch lever does not obstruct the cabin.

Helicopters in the three-tonne class are exemplified by the Eurocopter EC635, powered by two 452 kW Turbomeca Arrius 2B2 or 463 kW P&WC PW206B2 engines (designated EC635T2 and EC635P2 respectively). Fitted with a Fenestron tail rotor, this is one of the quietest helicopters in its class, and makes extensive use of composite materials. Useful features include clamshell doors at the rear of the fuselage. It can carry two 20 mm M621 cannon pods, or various anti-tank guided weapons. Production was launched in 1999 by an order for nine for the Portuguese Army. Others in this class include the MD Helicopters Explorer, with two PW207 engines. Explorers ordered by the Mexican Navy have provisions for a GDATP 12.7 mm GAU-19/A gun and a pod containing seven 70 mm rockets.

The three-tonne AgustaWestland A109M is the military version of the A109 Power, equipped in baseline form with two 530 kW PW207C or Arrius 2K2 engines. It can be used in a six-passenger utility role or (with HeliTow and up to eight Tow missiles) as a light anti-armour helicopter. Alternatively, it can be armed with a pintle-mounted 12.7 mm machine gun and the FN Herstal RMP pod, combining a 12.7 mm machine gun and three 70 mm rockets. The A109CM variant has two Rolls-Royce Model 250 engines, while the A109KM has Arriel 1K1s. Denel is to assemble 25 of the 30 Arrius 2K2-engined A109LUHs ordered by the South African National Defence Force to replace Alouette IIIs. Similar aircraft have been ordered by the US Coast Guard, the Italian and Nigerian Navies, and paramilitary agencies in China, Sweden and Switzerland.

The four-tonne, ten-seat Eurocopter/ Kawasaki EC145 or BK117C-2 is basically the older BK117C-1 with the front fuselage from the EC135, an enlarged cabin, two 550 kW Arriel 1E2 engines, more modern rotor blades, larger sliding doors and reduced external noise and interior vibration. It is primarily a civil helicopter aimed at the medevac market, although the French Army has ordered 32 for both casevac and search-and-rescue duties. The EC145 first flew in 1999.

In a slightly heavier category, the only version of the 4300 kg Eurocopter Panther with armament as standard is the naval AS565SB, powered by two 626 kW Arriel 2Cs. A military version of the wide-cabin five-tonne EC155 (the new designation for the Dauphin AS365N4) would be an EC655.

The military version of the new six-tonne Bell/Agusta Aerospace AB139 was designed as a Huey replacement and is able to carry 15 troops. The AB139 is powered by two 1380 kW P&WC PT6C-67C engines, and has high-set external stores to maximise the field of fire from two internally-mounted machine guns. Other features include a hexagonal-section fuselage for reduced radar response, a five-blade rotor and retractable landing gear.

Assault Helos

If the market really does demand an attack helicopter with a high degree of operational flexibility, then the 11,200 kg Mil Mi-24/35 series may suggest a worthwhile line of development. Although the concept of combining a tandem-seat front fuselage and a cabin that can accommodate eight fully-armed troops proved unattractive in the West, reports indicate that around 5000 Mi-24/35s have been built, and that several hundreds are still in service in around 50 countries. It is powered by two 1660 kW Klimov TV3-117VMA engines. The Mi-35 still appears to be built in small batches: the Czech Republic is accepting six as part of Russia's debt repayment.

Although an old basic design, having first flown in 1969, the Mi-24/35 is the subject of a multiplicity of upgrade programmes. The Mil design bureau and Rostvertol have developed the Mi-24M/ 35M, which has 1800 kW Klimov VK-2500 engines, a fixed landing gear and shorter wings to reduce empty weight, and the composite rotor blades of the Mi-28. It is proposed with night/adverse weather sensors and improved armament, including a turret-mounted twin-barrel 23 mm NPPU-23 cannon.

The Visegrad-4 group of nations, teaming the Czech Republic with Hungary, Poland, and Slovakia, is planning to upgrade around 115 Mi-24/35s for day/night bad weather operation and Nato compatibility, and to extend airframe life (in co-operation with Mil and Rostvertol) to keep the aircraft in service until 2015 to 2020. Systems integration is evidently to be performed by a Western company, such as BAE Systems, Sagem or Elbit. Other possibilities include IAI/ Tamam, which has developed a Mission 24 avionics and armament upgrade for the Indian Air Force, and South Africa's ATE, which has provided a Super Hind Mk II/III upgrade (based on Rooivalk experience) for the Algerian Air Force and one other operator.

The Mi-24/35 concept may have inspired the Hindustan Aeronautics (Hal) Light Combat Helicopter (LCH), which was shown in mock-up form at Aero India 2003. Based on the 4500 kg Advanced Light Helicopter (ALH) with two 740 kW Turbomeca TM333-2B engines, the LCH combines the twelve-passenger cabin of the ALH with a tandem-seat front fuselage, a 20 mm chin turret and wings with four hardpoints. The LCH is due to fly in 2005.

Armed Transports

The idea of arming light/medium transport helicopters is primarily a Russian concept, but it has been taken up to some extent in Western Europe and America, especially in the context of special missions. For example, by 2015 the French Air Force plans to have acquired 14 Eurocopter EC725s for special mission, anti-terrorism and Csar (Combat Search And Rescue) duties. Powered by two 1566 kW Turbomeca Makila 1A4 engines, the 11,200 kg EC725 will be armed with 20 mm cannon and rocket pods. Earlier versions of the Cougar series are used in the Csar role by Greece, Saudi Arabia and Turkey. The eight-tonne US Air Force Sikorsky MH-60G Pave Hawk is used for special missions and the Csar role, and is armed with 7.62 and 12.7 mm machine guns.

The eleven-tonne Mil-8/17 series, powered by Klimov TV3-series engines, is probably the world's most heavily armed transport helicopter. Over 10,000 have been built by Kazan and Ulan-Ude, and various armament and upgrade programmes are available. It can be armed (for example) with a 12.7 mm machine gun in the nose and four antitank guided missiles in combination with up to 192 unguided 57 mm rockets.
COPYRIGHT 2003 Armada International
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 2003, Gale Group. All rights reserved. Gale Group is a Thomson Corporation Company.

Article Details
Printer friendly Cite/link Email Feedback
Author:Braybrook, Roy
Publication:Armada International
Geographic Code:1USA
Date:Jun 1, 2003
Words:2441
Previous Article:A fast moving drone world: unquestionably, the drone world is one of the fastest moving sectors of the defence industry. This page provides a brief...
Next Article:Winding up the whirly attackers. (Upgrade Approach).
Topics:


Related Articles
US anti-tank missile developments.
Anti-tank guided missile developments.
A wolf in sheep's clothing: although lacking the speed, manoeuvrability and small target area of a dedicated attack helicopter, a utility or...
Marine Corps Aviation around the globe.
Military aircraft market: who, why, when? As the commercial transport market remains depressed, aircraft manufacturers are looking urgently for...
Punch from the air.
Bolt from the blue: as aerial combat becomes a distant memory, the emphasis in aircraft armament is now on the ground attack role, with growing...
Weapons for whirlybirds.
Unmanned, but now armed.

Terms of use | Copyright © 2018 Farlex, Inc. | Feedback | For webmasters