Defence 21 Magazine,English Supplement,Issue-45.pdf

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HE MENA REGION DEFENCE, SECURITY AND AEROSPACE MAGAZINE FOR THE 21st CENTURY

www.defence21.com

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A better viewIn-theatre communications systems

ensure the dissemination of informa-

tion around the battlefield, both verti-

cally and horizontally. The secure

free flow of this information within

potentially disruptive signalling envi-

ENGLISH SUPPLEMENT 177

Defence 21 • Volume 8 • Issue N˚45 • December 2011 - January 2012 ´ÉaO21•áæeÉãdG áæ°ùdG•¿ƒ©HQC’Gh ¢ùeÉÿG Oó©dG• Èª°ùjO /∫hC’G ¿ƒfÉc2011 ôjÉæj /ÊÉãdG ¿ƒfÉc -

Strategic Communication Systems: System Essential

for Expeditionary and Specialized Forces

Earlier this year images of the US government’s reaction to the

killing of Osama Bin Laden were flashed around the world.

Photographs taken inside the Whitehouse showed the government’s

inner circle, including President Obama, watching a live video feed of

the attack on Osama’s compound by US Navy SEALS operating

under the direction of Joint Special Operations Command in cooper-

ation with the CIA.

These images show how much the reality of strategic communica-

tions systems have changed over the past decade. Military command-

ers thousands of miles away from operations can be kept informed of

events and can remain in contact with forces on the ground as commu-

nications technology has advanced. Not only are communications at

the tactical and theatre level more advanced than ever before, the dis-

tance between homeland operational headquarters and operational

environments have effectively shrunk, bringing real-time strategiccommunications between different echelons of military forces into

closer contact.

‘The US government was in live contact with special forces troops during the raid and killing of

Osama Bin Laden’, (Wikimedia).

ronment is a vital battle winning abil-

ity, and all levels of the overall infor-

mation system must operate in con-

cert to deliver the right communica-

tions to the right people at all levels.

In the UK armed forces, the British

Army utilises a number of communi-

cations systems to deliver this capa-

bility. The Cormorant System, a the-

atre-deployable communications net-

work for the Joint Task Force

Headquarters, (JTFHQ), providing

communications support for direct

subscribers at Joint Force and other

deployed Component Command

Headquarters; while the FALCON

systems provides a resilient commu-nications system that is flexible

enough to support operations across

the full spectrum of conflict, as well

as being interoperable within the joint

and multinational environment, and

with legacy systems, using Internet

Protocol technology to provide a high

capacity, tactical, formation level

secure, communications system for

the ARRC, RAF and UK Divisions

and Brigades. At the tactical level, the

BOWMAN family of tactical radios

provides the British Army with HF,

VHF and UHF voice and data com-

munications from formation head-

quarters forward to the fighting units,

with the system designed to provide

an integrated digital communications

network across the battlefield by

interfacing with higher level systems

and networks such as ISDN, Skynet

V, Cormorant and FALCON.

At the top end of the communica-tion systems sits the satellite commu-

nication (SATCOM) capability in

three systems, to provide strategic

and operational satellite communica-

tions for all land-based headquarters.

Small SATCOM is provided by the

SWE-DISH CCT-120 satellite

ground terminal owned by Paradigm.

The terminal uses the SKYNET5 net-

Claire Apthorp





work to provide an assured service to

users on worldwide operations. The

satellite ground terminal is light-

weight, transportable within an air-

frame and can be set up by a single

trained operator in less than 30 min-

utes, and is currently in service with

high readiness units. The cornerstone

of the satellite communications termi-

nals for the UK Ministry of Defence

(MOD) is the Reacher family of satel-

lite ground terminals. Also owned by

Paradigm these terminals deliver

satellite communications via secure,

robust and resilient communications

links.

Skynet 5 itself is the network of

satellites operated by Paradigm on the

behalf of the UK MOD that provide

the capability to extend the range of

in-theatre communication systems

such as the Falcon and Cormorant tostrategic lengths. Via a connection to

the UK fixed communications sys-

tems, information dispersed in-theatre

by forces on UK and Coalition tasks

can be communicated back to the UK,

as well as to land, sea and air plat-

forms, for the greater cohesion of the

battlefield picture across all com-

mand levels.

The Skynet 5 satellites are managed

by Paradigm as part of a contract

between the UK MOD and Astrium,

of which Paradigm Secure

Communications is a subsidiary, and

will see satellite communications

services provided until at least 2022.

Four Skynet 5 next-generation satel-

lites are being provided for the pro-

gramme, as well as a major upgrade

of the fixed terrestrial infrastructure,

networks and management systems in

the UK, and over 160 satellite com-

munications terminals. The Skynet 5

system provides reliable secure voice

and data communications for peace-

keeping and battlefield UK Armed

Force operations, each carrying

advanced UHF and SHF communica-

tions payloads and 15 active channels

and extensive channel to beam flexi-

bility as well as multiple antennas for

global and regional spot beams. Theground components include 59

Reacher tactical vehicle-mounted

units in various configurations.

Astrium was also involved in the

German Armed Forces SATCOMBw

programme, which saw the provision

of a dedicated military satellite sys-

WAS satellite.jpg, ‘The Boeing WAS satellite’, (Boeing).

“The Boeing Wideband Global SATCOM payload block diagram’, (Boeing).



tem for secure military communica-

tions. The programme enables inde-

pendent infrastructure for internation-

ally deployed troops to communicate

via their own secure information net-

work, with full autonomous transmis-

sion of voice, data and multimedia

applications around the globe. Two

satellites were launched under the

programme (COMSATBw 1 & 2),

with the first satellite launched in

2009 and the second the followingyear. Together they provide commu-

nication services over an area stretch-

ing from North America to Eastern

Asia. SATCOMBw Stage 2 also

includes the delivery of a comprehen-

sive ground user terminal segment,

both fixed and transportable equip-

ment, and the upgrade of the network

management centre already installed

with the German Armed Forces.

Joint effortsThe use of SATCOM assets for

communicating with deployed troops

from home territory is effective, espe-

cially in areas where no existing

infrastructure permits standard oper-

ating networks; but remains in the

reach of only those nations with the

budget to access the technology. The

launch and maintenance of dedicatedmilitary satellites is expensive as is

the leasing of commercial satellites

for military use. For this reason there

is a growing trend for governments to

combine resources in order to provide

communications for their special

forces deep in theatre, as well as for

secure communications among allied

nations.

The US Armed Force Wideband

Global SATCOM (WGS) system has

been designed to meet the strategic

communication requirements of both

the US and the Australian militaries.

It provides flexible and high-capacity

communications for the US Army’s

mobile ground forces, the Air Force’s

airborne terminals, the Navy’s

deployed vessels, White House

secure communications, the US State

Department and special users.

Australia’s government bought into

the programme in 2007 at a cost of

AUD $2 billion rather than invest in

the development of an Australian-

only programme, bringing a next-generation SATCOM capabilities to

the Australian Defence Force (ADF).

The project will add additional

capability elements of an HQ Joint

Operations Command Preparedness

Management Information System, as

well as bringing improvements to sit-

uational awareness and the provision

of a Special Operations Combat Net

Radio Interface for the ADF. The

Australian portion of the project will

involve the development of a satellite

remote control capability in Australia,

and will enable Australia to lessen its

reliance on the Singtel/Optus C1

satellite, which is partially owned by

the Singapore government.

The WGS programme is based on

Boeing’s model 702 commercial

satellite. In total six satellites will be

launched, which will bring the US

Department of Defence (DOD) its

highest-capacity communicationssatellite network. Each WGS satellite

can route 2.1 to 3.6 Gbps of data pro-

viding more than ten times the com-

munications capacity of the predeces-

sor DSCS III satellite. Depending on

the mix of ground terminals, data

rates and modulation schemes

employed, each satellite can support

data transmission rates ranging from



Global.jpg, ‘Strategic communications technology is shortening the distance between the battle-

field and the homeland’. (Boeing).



2.1 Gbps to more than 3.6 Gbps.

The system uses reconfigurable

antennas and a digital channeliser that

divides the uplink bandwidth into

nearly 1,900 independently routable

2.6 MHz subchannels, providing con-

nectivity from any uplink coverage

area to any downlink coverage area,

and supports multicast and broadcast

services as well as providing an effec-tive and flexible uplink spectrum-

monitoring capability to support net-

work control. The system is also able

to connect X-band and Ka-band users

anywhere within the satellite field of

view. This provides substantial oper-

ational flexibility and delivers the

capacity, coverage, connectivity and

control needed to support demanding

operational scenarios.

The WGS design includes 19 inde-

pendent coverage areas that can bepositioned throughout the field of

view of each satellite. This includes

eight steerable and shapeable X-band

beams formed by separate transmit

and receive phased arrays; 10 Ka-

band beams served by independently

steerable, diplexed antennas, includ-

ing three with selectable RF polariza-

tion; and transmit/receive X-band

Earth coverage beams.

The first three Block I WGS satel-

lites are operational, and are stationed

over the Middle East, the Pacific

Region, Europe and Africa. The

remaining three satellites are to be

Block II systems with launches

scheduled for 2012-2013. The Block

II satellites add a radio frequency

bypass capability designed to support

airborne intelligence, surveillance

and reconnaissance platforms requir-

ing ultra-high bandwidth and data

rates demanded by unmanned aerial

vehicles; and Boeing is continuously

working with the US Air Force on

ways to evolve the capability of the

system to better support warfighter

communications.

As modern warfare evolves, the use

of effective SATCOM for strategic

communications will continue to

grow. The importance of a secure

communications system that can pro-

vide connect military forces working

together is vital, as the future of war-fare will see coalition operations

dominate the battlefield. And as the

raid on Osama Bin Laden’s com-

pound illustrates, the use of special

operation forces operating deep with-

in the battlefield will increase, forcing

a reliance on communication net-

works that can support strategic con-

nectivity in areas where there is little

or no existing infrastructure.



SATCOM provide strategic and operational satellite communications for all Land-based headquar-

ters. Photo: EADS

PARADIGM SERVICES Ground Systems. Photo: EADS

¯



Laser gunsWhile the future of the Airborne

Laser programme remains uncertain,

as the USAF has not requested any

additional funds to move the project

forward, the platform has demonstrat-

ed that it can intercept and destroy a

simulated liquid-fuelled ballistic mis-

sile. This occurred during a test at

Point Mugu Naval Air Warfare

Centre off the California coast in

March 2007. Chemical lasers are just

one of a range of capabilities that are

grouped together under the terms

‘Directed Energy Weapons’.



Directed Energy Weapons: Is It Ready For

C-RAM Operations?

‘Peace through light’ is the wry nickname bestowed on theUnited States Air Force (USAF) Boeing YAL-1 Airborne Laser

programme which uses a Boeing 747-mounted chemical oxygen iodine

laser designed to shoot down tactical ballistic missiles during their so-

called ‘boost phase’. The boost phase covers the stage in a missile’s

flight envelope before it reaches an altitude of 150-200 kilometres.

NC-130H (USAF) – The USAF has outfitted a Lockheed Martin C-130H Hercules transport air-

craft with a chemical laser which has performed flight trials during which it was able to hit ground

targets at White Sands Missile Range in New Mexico.

One of the key attractions of lasers

are their velocity, which is measured

at a shade over one million kilometres

per hour; the speed of light. This

allows a laser to hit any fast-moving

mobile target as theoretically, nothingcan travel faster than light speed.

Additional attractions include their

invulnerability to the effects of gravi-

ty to which bullets, missile and shells

must eventually succumb. Moreover,

lasers do not produce recoil and do

not depend on a supply of ammuni-

tion.

However, despite their ‘wonder-

weapon’ credentials, lasers do have

limitations. Firstly, they are vulnera-

ble to weather. Atmospheric contami-

nants such as fog, dust, smoke and

rain can cause the laser to ‘bloom’; a

phenomenon during which the beam

becomes de-focused and looses some

of its destructive effect. Cost is anoth-

er issue. Lasers which can engage

ballistic missiles are not cheap. This

is chiefly because of the highly

sophisticated components with which

they must be equipped. These include

high-specification mirrors to focus

the light onto the target. Running

costs are another potential problem aslaser weapons have an epic appetite

for electricity. To provide a

Newtonian analogy, one apple falling

to earth releases one joule of energy.

Thus a one megajoule laser develops

the equivalent energy of one million

apples falling to the ground simulta-

neously, or the equivalent kinetic

effect of a one-tonne vehicle travel-





ling at 160km/h. Thus the resulting

destructive power of a one megajoule

laser is equivalent to the detonation of

200 grams of explosives. This is

notably less than the 9.4kg warhead

carried by a Raytheon AIM-9

Sidewinder air-to-air missile, but

enough to cause significant damage to

a tactical ballistic missile. The laser

can vaporise the missiles’ surface,

perhaps exposing and damaging

flight control systems with extreme

heat, or causing the fuel to ignite and

the missile to loose control.

While a Boeing 747-based platform

provides the necessary energy to hit

missiles, there is, at present, no satis-factory way with which electricity

can be stored and conducted to enable

destructive lasers to be introduced

into handheld weapons. One of the

side-effects of the huge levels of ener-

gy that lasers require is the resulting

heat they generate. Therefore, they

need large and complex cooling sys-

tems to ensure they can both function

and maintain a good rate of fire to

cope, in the case of the Airborne

Laser, with multiple missile launches.

In the missile defence role, this is par-

ticularly important as an adversary

may choose to fire salvoes of missiles

to increase their chances of scoring a

successful hit on one, or several, tar-

gets. Finally lasers are also, by their

very nature, line of sight weapons.

This prevents them being used for

indirect fire in a similar fashion to

conventional artillery as laser light

simply does not bend. The result of

this is that the platform carrying the

laser, be it an aircraft or a large ocean-

going warship, must be down range

of the target that it is trying to destroy.

This denies the firing platform the

comparative safety of being posi-tioned over-the-horizon.

MIRACL and MLDThe US Navy has shown similar

interest to the USAF in laser

weapons, notably via its Mid-Infrared

Advanced Chemical Laser (MIRA-

CL) programme. The development of

this deuterium fluoride laser can be

traced back to the early 1980s when

the MIRACL initiative commenced

to develop a laser which could inter-

cept and destroy anti-ship missiles.

That said, MIRACL was also pro-

posed as an anti-ballistic missile and

anti-satellite weapon, disabling a

satellite at 432km altitude to this end

during a test in 1997. The work pio-

neered by the US Navy regarding

MIRACL allowed it to move forward

with the Maritime Laser

Demonstrator (MLB) initiative which

involves Northrop Grumman.

In early April, Northrop Grumman

and the US Navy were successful in

disabling a small water-borne target

with the MLD, which was fired from

the deck of the USS Paul F. Foster; a

decommissioned Spruance classdestroyer outfitted with a high-pow-

ered laser for the test. One of the

applications being mooted for the

MLD is to provide navy vessels with

a point defence against small boats

which may be carrying explosives or

suicide bombers. In addition to the

disabling of the small craft by laser,

the navy has demonstrated that it can

integrate the MLD with a ships’

radar, and use the laser in conditions

of high atmospheric humidity. As

Maritime Laser Demonstrator (Northrop Grumman) – Northrop Grumman is working with the US Navy on developing the Maritime Laser

Demonstrator. Envisaged as a means by which warships could mount a local defence against small boats, its destructive effects are clearly illustrat-

ed by this photo.



noted above, the presence of water

droplets in the air can sometimes

cause significant disruption to lasers.

THELWhile both the US Navy and the

USAF have been pouring investment

into lasers, such technology has not

been neglected by the US Army.

Along with its work on the MLD,

Northrop Grumman is involved with

the Tactical High Energy Laser

(THEL) initiative. Working alongside

the US Space and Missile Defense

Command, based in Huntsville,

Alabama; and the Israeli Ministry of

Defence; the THEL, like MIRACL

(see above) employs a deuterium flu-

oride chemical laser. Also included

on the system is a fire control radar;command and control system; plus

acquisition, tracking and pointing

equipment. Between 2000 and 2005,

the THEL performed tests against

simulated rocket, artillery and mortar

fire destroying 28 Katyusha rockets,

fired both in salvoes and in surprise

attacks, five artillery shells, three

rockets; ten mortar rounds fired in

salvoes and fired singularly; and a

mix of light, medium and heavy rock-

ets. At present, the THEL test bed has

been transferred for use to the US

Army’s High Energy Laser Test

Facility in New Mexico.

MicrowavesNevertheless, directed energy

weapons are not restricted to lasers.

Microwave energy, for example, has

been muted for applications such as

crowd control. Put simply,

microwaves produce heat, hence their

use for cooking. The US Army has

already trialled microwave-based sys-

tems which can heat the surface of a

person’s skin to a temperature of

around 54ºC causing significant dis-

comfort from a range of up to 460m.This research has been incorporated

into crowd control measures, notably

in the form of the US Army’s Active

Denial System (ADS). The ADS is

mounted on board an AM General

HMMWV (High Mobility

Multipurpose Wheeled Vehicle) and

emits a millimetre wave of circa 95

gigahertz. Those exposed to the ADS

note that their skin begins to heat up,

and the longer that one stands in

range of the microwaves, the stronger

the sensation is until it cause signifi-

cant discomfort. As soon as a person

stands away from the microwave

emitter, their skin rapidly cools down.

The sensation has been likened to the

feeling of heat upon one’s face after

opening the door of a very hot oven.

Although the ADS deployed to

Afghanistan in 2010 for crowd con-

trol, it was not thought to have been

used. While the ADS’s effectiveness

seems to lie in the fact that it causes

discomfort, microwave weapons are

not without controversy amid con-cerns that they could have the poten-

tial to cause serious injury. The con-

tentious nature of these weapons may

mean that, for now, they remain off

limits for use against civilians, and

instead have their application restrict-

ed to Electronic Warfare (EW).

NKCEIn fact research into microwave

applications for EW received a boost

in late-2010 following a $230,000

contract award to Lockheed Martin

by the USAF, to define the design

requirements for a high-powered

microwave energy beam designed to

disrupt and destroy enemy electronic

systems. Under the auspices of the

‘Non-Kinetic Counter Electronics

Capability' (NKCE) study, the com-

pany is defining the system require-

ments for such a weapon, and how it

could be carried on an aircraft.The NKCE is an important step

towards eventually fielding a weapon

which could be used to damage elec-

tronic circuits in a similar fashion to

the Electro-Magnetic Pulse (EMP)

which accompanies a nuclear explo-

sion. In terms of the timeframe to

field such a weapon this could take up

to eight years, depending on its even-



THEL (US Army) – The US Army’s directed energy research has focused on the Tactical High

Energy Laser (THEL), the development of which has also involved Northrop Grumman. The THEL

could form the basis of a system to destroy hostile rocket, mortar and artillery fire.



tual design. Interest in producing

EMP-style effects on electronic

equipment has been around since the

capacity of nuclear explosions to

cause such disruption was first

observed in the late 1940s. Since

then, scientific research has focused

on making the power supply and

ancillary components, such as the

magnetic field producing systems

generating the microwave radiation,

sufficiently compact to fit onto an air-

borne platform. Moreover, although

progress is occuring regarding the

realisation of a practical weapon,

such a system will still require higher

density batteries and higher energycapacitors compared to those avail-

able today.

Whereas the EMP accompanying a

nuclear explosion will damage all

unshielded electronic equipment

indiscriminately, a microwave

weapon could be designed in such a

manner to reduce the danger of the

emission causing damage to friendly

aircraft or electronic systems nearby.

This could be achieved via the use of

a directional antenna which would

transmit the microwave energy

towards the targeted equipment. As

today’s, and tomorrow’s, battlefields

feature an increasing number of sys-

tems dependent on electronics for

command, control, communications,

surveillance and reconnaissance, so

the microwave weapon will have

more targets to attack. One obvious

application is to assist in the

Suppression of Enemy Air Defence(SEAD) mission by using microwave

energy to disrupt air search and fire

control radar for surface-to-air missile

batteries.

One of the key attractions of the

microwave weapon concept is that it

potentially causes serious damage to

electronic circuits, without posing a

danger to humans. The output power

required by a microwave weapon is in

the region of one gigawatt, or higher,

although this would be emitted for an

extremely short period of time; typi-

cally around one hundred nanosec-

onds. The energy contained in one

pulse would be around one hundred

joules. Therefore, a ten-shot burst

would give a total of power output of

one kilojoule. This would be the

equivalent of running a one kilowatt

microwave oven for around one sec-

ond.

Science fact?In the short term, following the

conclusion of Lockheed Martin’s

work, the US Government is expected

to make a decision in 2012 as to

whether to embark upon future devel-

opment of a microwave weapon for

an airborne platform. While, as the

NKCE programme has illustrated,

directed energy weapons are enthusi-

astically being pursued in the United

States there arguably remains signifi-

cant work still to be done until they

are ready for large scale deployment.

Although it has portrayed directed

energy weapons such as lasers since

the earliest days of the genre in the

Nineteenth Century, turning science

fiction into military fact will still take

some time. T.W.



YAL-1 (Boeing) – The United States Air Force YAL-1 airborne laser has performed flight trials

during which it has demonstrated its capability of hitting ballistic missiles during the boost phase.

However, the programme’s future remains uncertain because of funding issues.

¯





Border Security UAVs

The use of unmanned aerial vehicles (UAVs) for border patrol

missions is increasing in popularity as operators come to realisethe benefits of utilising the technology in this way. Border patrol, both

terrestrial and maritime, has traditionally been carried out by

manned patrol platforms, and in the majority of nations, still is. The

use of manned fixed wing and rotary platforms for this purpose how-

ever, is a resource-heavy and expensive pursuit, and as UAV technol-

ogy becomes more effective and inexpensive, its deployment will con-

tinue to develop as manufacturers focus on this market segment.

The threats to national security posed by unpatrolled borders are

significant and are constantly shifting as geo-political and terrorist

conflicts evolve. The last decade has seen a change in both the types

of threats to border areas, and how those threats are executed, result-

ing in a rethink in the type and number of resources required to meet

the challenge effectively.

For border patrol organisations, be they military or para-military,

the task of keeping national areas protected against illicit activity is

complex. Land borders must be continuously protected against illegal

crossings, maritime borders can incorporate vast bodies of water and

land that must be kept clear of inappropriate immigration, drug

smuggling and organised offensive attacks, and an increasing number

of operators are integrating UAV systems onto Offshore Patrol

Vessels (OPVs) to better control these areas.

Combined assetsEarlier this year it was announced

that the DCNS shipbuilding company

had formed a deal with Schiebel for

the purpose of deploying the

Camcopter S-100 vertical take-off

and landing (VTOL) UAV onboard a

new class of OPV for the French

Navy. The Gowind Class L’Adriot

was designed to conduct maritime

surveillance and reconnaissance mis-

sions, as well as anti-piracy and anti-

smuggling operations, and is the first

vessel to be designed and built to pur-

posely carry a UAV.

The use of a small UAV and OPV

to work in concert to perform mar-

itime border surveillance enables

wider areas of influence to be

patrolled, as well as real-time situa-

tional assessments and faster decision

making. By sending the Camcopter S-100 out to gain closer observation of

suspicious vessels and activity and

receiving data back in real time, the

UAV effectively becomes an exten-

sion of the ship’s radar and sensor

system.

The Camcopter S-100 will carry the

Thales Optronique Agile 2 Electro

Optical and Infra Red (EO/IR) sensor

payload in order to observe, carry out

stand-off surveillance and distance

tracking of ships. And being much

smaller than a manned helicopter, the

UAV takes up a very small amount of

deck space and requires a smaller

maintenance and operator team. The

Camcopter S-100 is a proven civil

and military capability for a wide

range of purposes and does not

require any supporting launch or

Camcopter.jpg, ‘The Camcopter S-100 has been selected for the DCNS programme

for the French Navy’, (Scheibel).





recovery equipment; and can perform

under adverse weather conditions, on

land and at sea. The Camcopter S-100

is also available with an external fuel

tank for extended range and

endurance. This option increases

flight time to up to 10 hours and has

already been delivered to a US cus-

tomer. Additional enhancements

include the ability to carry external

suspended under-slung loads and

increased electrical power output for

payloads, as options for the CAM-

COPTER S-100, broadening the

reach of the system’s mission abili-

ties.

In preparation for the deployment,

Schiebel carried out a number of trials

to demonstrate the suitability and ver-

satility of a VTOL UAV in the mar-

itime domain from a coastal setting.

‘Set ups like these, where UAVs

work in close collaboration with mar-

itime patrols, will ensure safer board-

ers and maritime areas for the opera-

tors’, Neil Hunter of Schiebel told

Defence 21. ‘And while operating a

UAV off the back of a ship is much

more challenging than operating one

from land, once the UAV is in the air

the operation itself is much easier

because once you are outside territori-

al waters there aren’t the same restric-

tions on airspace that there is over

land. This in itself will push the door

open a bit wider for the use of UAVs

both for maritime patrols and over

land, to protect coastlines, offshore

infrastructure and terrestrial borders’.

Opening doorsThe use of UAVs for border patrol

is still in the relatively early stages of

adoption, but manufacturers are see-

ing additional penetration opportuni-

ties within the market as more mis-

sion capabilities are enabled.

‘We are looking at new types of

payloads in order to gain maximum

value from what is a very robust plat-

form that occupies a very valuable

Global Hawk flight.jpg, ‘The Global Hawk can be deployed along borders for wide area surveil-

lance’, (Northrop Grumman).

Global Hawk.jpg, ‘The Global Hawk can survey large geographic areas with pinpoint accuracy’,(Northrop Grumman).



location within the operator’s asset

hierarchy’, Steve Gitlin of

AeroVironment said. ‘Importantly,

this includes the growing adoption of

platforms able to carry out a range of

missions for increased cost-effective-

ness.’

AeroVironment’s Raven B UAV,

originally designed for battlefield

Intelligence, Surveillance and

Reconnaissance (ISR), is able to per-

form fast-deploy low-altitude opera-

tions for a range of missions includ-

ing border patrol, which Gitlin sees as

a significant future opportunity. With

a wingspan of 4.5 feet and a weight of

4.2 pounds, the hand-launched Raven

provides day or night aerial observa-tion at line-of-sight ranges up to 10

km. The Raven delivers real-time

colour or infrared imagery to the

ground control and remote viewing

stations, and can operate manually or

can be programmed for autonomous

operation utilising the system’s

advanced avionics and precise GPS

navigation.

The benefits of using small, hand-

launched UAVs for use in border

patrol are many. Their silent opera-

tion allows operators to increase their

field of view over suspicious activity

or problem areas while maintaining a

stand-off range, but there are still hur-

dles to be crossed before adoption can

truly take hold.

‘This para-military application is

very attractive, but right now it is lim-

ited by civil airspace regulations, and

here in the US the FAA does not

allow unmanned systems to operate

unless granted a very narrow certifi-

cate of operation. We are in involved

in getting this changed, as well as

developing new breakthrough solu-

tions that will open up new market

opportunities’, Gitlin said.

Up in the air some-where

At the very top end of the UAV

spectrum is the High Altitude LongEndurance (HALE) category of air-

craft. These systems are designed to

fly at almost twice the height of com-

mercial aircraft to provide operators

with airborne wide-area surveillance

and reconnaissance. With signals

intelligence (SIGINT) mission sys-

tem payloads the system provides a

stand-off capability to detect elec-

tronic and communications emitters,

HALE aircraft, such as the Northrop

Grumman Global Hawk, effectively

act as an affordable, manoeuvrable



Predator B.jpg, ‘A CBP Border Patrol agent uses the remote to steer a border patrol UAV’, (CBP).

Predator B UAV platform has been supplied to the US Customs and Border Protection agency

(CBP) for use in homeland security operations



and deployable satellite.

The system can survey large geo-

graphic areas with pinpoint accuracy,

giving decision-makers real-time

information regarding activities,

resources and personnel. Once mis-

sion parameters are programmed into

Global Hawk, the air vehicle can

autonomously taxi, take off, fly,

remain on station capturing imagery,

return, and land, while ground-based

operators monitor the system’s health

and status, and can re-task the air sys-

tem’s navigation and sensor plans

during flight as necessary.

‘These systems will become very

attractive to nations that cannot affordtheir own communications satellites,

and need a versatile substitute,’ Ed

Walby of Northrop Grumman said.

And unlike satellites that are limited

to their own orbit, HALE platforms

can be deployed to observe and report

back on any number of occurrences,

including natural disasters, manmade

disasters, and border security opera-

tions, such as the highly fraught land

border between North Korea and

South Korea, where a platform with

advanced-performance observation

capabilities becomes highly valuable.

But while the HALE market has a

lot to offer, its uptake is limited at the

moment to a few nations with the

means and requirements for such a

platform. On the other hand, a plat-

form such as the Global Hawk (or

Euro Hawk in Europe) has significant

latent value in its multi-purpose

nature, particularly as governmentslook to streamline their defence plat-

forms to get as much as possible out

of each asset that it invests in.

Transparent informa-tion

This drive toward multi-mission

platforms is also reaching down to the

smaller UAV categories. In particular

the move toward network-centric

warfare (NCW) is a big factor in this,

as operators seek to make the infor-

mation gathered by the UAV distrib-

uted to the widest possible audience

who may have an interest in that intel-

ligence. The addition of plug-and-

play software is helping here greatly,

when combined with additional

removable payloads, a standard bat-

tlefield ISR platform can be easily

transformed into a maritime surveil-

lance aircraft.

General Atomics sees a remarkable

opportunity in this area. Their

Predator B UAV platform has been

supplied to the US Customs andBorder Protection agency (CBP) for

use in homeland security operations.

Known as the Guardian aircraft, the

UAV is equipped with maritime sen-

sors to detect the small and fast ves-

sels that are used for drug smuggling

operations. The Department of

Homeland Security (DHS) also uses

the aircraft daily in operations to

patrol land borders including the US-

Mexico border, as well as the north-

ern border with Canada.

The Guardian has been modified

from a standard Predator B with

structural, avionics, and communica-

tions enhancements, as well as the

addition of a Raytheon SeaVue

Marine Search Radar and an Electro-

optical/Infrared (EO/IR) Sensor that

is optimized for maritime operations.

DHS plans to eventually operate a

networked unit of Guardian aircraft

and ground control stations (GCS)

along US borders to keep these valu-

able domains secure.With operators such as the US mak-

ing clear progress with the use of

UAVs for border security, the future

is looking bright for future adoption

by additional operators seeking a ver-

satile and inexpensive alternative to

manned patrols.

D.L.



AeroVironment’s Raven B UAV, originally designed for battlefield Intelligence, Surveillance and

Reconnaissance (ISR)

¯



BahrainThe Royal Bahraini Air Force

(RBAF), for example, is responsible

for a significant proportion of the

nation’s ADGE, alongside the coun-

try’s combat aircraft (excluding naval

helicopters). The country is pouring

investment, and know how, into

enhancing the security of its skies via

the Hizam Al Taawun (‘Belt of

Cooperation’) regional GBAD initia-



tive. Involving Kuwait, Oman, Qatar,

Saudi Arabia and the United ArabEmirates (UAE) Hizam Al Taawun

effectively connects together the

national Integrated Air Defence

Systems (IADS) of these countries

via high-speed fibre optic encrypted

data links. Although information

regarding the exact workings of the

Hizam Al Taawun is scant, it is

thought that the national recognised

air picture from each participant

nation can be transmitted to its coun-

terparts; along with written, carto-

graphical and possibly voice commu-

nications. The RBAF’s GBAD capa-

bilities have received a recent boost

with the acquisition of a transportable

Lockheed Martin AN/TPS-59(V3)

solid-state L-band air search radar

which can detect incoming tacticalballistic missiles at 400 nautical

miles’ (740 kilometres’) range, and

164nm (305km) altitude. In addition

to the acquisition of the AN/TPS-

59(V3) radar, the RBAF is expected

to acquire Raytheon MIM-104 Patriot

Surface-to-Air Missile (SAM) sys-

tems for territorial defence. It is pos-

sible that these could be integrated

into a network with the AN/TPS-

59(V3) in order to provide a nationaltactical missile defence system.

IranBahrain’s ADGE enhancements, in

terms of its radar and expected SAM

acquisitions, are largely reflect

national concerns regarding Iran’s

development of ballistic missile tech-

nology. Iran itself is seemingly aware

of the disquiet that its ballistic missile

ambitions are causing in the Gulf, and

in the wider world. Although attemptsby the international community to

persuade Tehran to forgo its missile

programmes, and its alleged develop-

ment of Weapons of Mass

Destruction (WMD), has so far fol-

lowed a diplomatic course, the area

remains a potential flashpoint for mil-

itary action.

Tehran is clearly cognisant that the

Gulf Air Forces

Executives at France’s Dassault Aviation are no doubt biting

their nails following the announcement on 17th October by

Gerard Longuet, the country’s defence minister that Paris was in the

final stages of negotiations to sell the United Arab Emirates (UAE) up

to 60 Rafale F3 combat aircraft for around $10 billion. Should the deal

go through, the UAE would become the first export sale for this air-

craft, which equips France’s Aeronavale (Naval Aviation) and Armée

de l’Air (French Air Force). The UAE’s possible Rafale acquisition is

just one of several air force programmes ongoing around the Gulf

which is witnessing a region-wide enhancement of fixed- and rotary-

wing aircraft, and Air Defence Ground Environment (ADGE) equip-

ment.

Eurofighter Typhoon (Eurofighter GmbH) – So far, the Eurofighter Typhoon has won customers

in Saudi Arabia and, outside the Gulf, Austria. Oman is looking increasingly likely as the third

export customer for the multirole combat aircraft.

Thomas Withington (*)





current uneasy stand off over its

WMD and ballistic missile ambitions

could escalate into war. With this in

mind, an extensive reorganisation of

the country’s air force is occurring via

which this service will assume much

of the ADGE responsibility. The air

defence assets currently operated by

the army include circa 150 MIM-23

Hawk SAMs; plus an unknown num-

ber of 9K32 Strela-2 (NATO report-

ing name SA-7 Grail), Raytheon

FIM-92 Stinger, Shahid Shah Abhady

Industrial Complex Misagh-1/-2 and

RBS-70 Man-Portable Air Defence

Systems (MANPADS), in addition to

approximately 29 Almaz-Antey9K330 Tor-M1 (NATO reporting

name SA-15 Gauntlet) tracked

short/medium-altitude SAM plat-

forms, will come under the air force’s

command. These systems join the

circa 1,800 towed 23mm, 35mm,

40mm, 57mm, and 85mm Anti-

Aircraft Artillery (AAA) pieces,

operated by the army, and its 100

ZSU-57-2 Ob’yekt-500 and ZSU-23-

4 Shilka self-propelled AAA. The air

force, for its part, operates around 200

MBDA/BAE Systems Rapier short-

range air defence (SHORAD) SAMs.

All of these platforms will now be

placed together under air force con-

trol.

Much has been made in the press

regarding Iran’s plans to receive five

NPO Almaz S300 (NATO reporting

name SA-10 Grumble) high-altitude

SAM systems from Russia. This con-

tract was cancelled in September2010 amid fears that it could breach

United Nations sanctions in place on

Iran. However, some reports have

claimed that the country has already

received four S300 systems, two of

which were acquired from Belarus,

and another two which arrived from

an undisclosed country. In a further

twist, on 17th October, General

Shahrokh Shahram, one of Iran’s sen-

ior military commanders, announced

that the country was developing a

SAM system known as the Bavar-

373, which he claimed eclipsed the

S300 as regards its performance

against manned aircraft and cruise

missiles. The decision to develop the

Bavar-373 was said by General

Shahram to be a response to Russia’s

refusal to deliver the S300. Iran is no

doubt anxious to modernise its air

defences. While the numerical paper

strength of its capabilities appear

strong, one must bear in mind that

several of the systems upon which it

relies, notably the Hawk, Stinger,Rapier are ageing.

IraqAcross Iran’s eastern border, its

Iraqi neighbour is modernising its air

force. Although, unlike Iran and

Bahrain, Iraq’s air force does not pos-

sess any ADGE systems, it is looking

to modernise its fixed- and rotary-

wing capabilities. The country has

had a long-standing requirement to

procure up to 18 Lockheed Martin F-

16C/D Block-50/52+ (locally desig-

nated F-16IQ) multirole combat air-

craft, with an increase in the number

to be procured possibly rising to 36.

Furthermore, the country is known to

be interested in buying up to 36

Hawker Beechcraft AT-6B counter-

insurgency/light attack aircraft. The

transport fleet, which includes three

Lockheed Martin C-130E Hercules,

will be enhanced with the delivery of

four C-130J variants in the coming

years. Rotary assets have not been

neglected in this over-arching mod-

ernisation with 22 Mil Mi-17E

(NATO reporting name ‘Hip’) armed

utility helicopters due to arrive by the

end of the year to supplement the 24Eurocopter EC-635 aircraft on order,

and the six Eurocopter SA-342

Gazelle aircraft, armed with 20mm

cannon which were delivered in 2010.

JordanLikewise, new trainers are on the

wish list of the Royal Jordanian Air

Force (RJAF). Presently, the service

uses CASA C-101 Aviojets as a lead-

in jet trainer, although these are des-

tined to be replaced by a new aircraft.

Candidates to fulfil this requirement

C-130J (Lockheed Martin) – Lockheed Martin’s C-130J family of freighters has sold well across

the Gulf region. Iraq is developing the fixed wing transport fleet of its air force with this version of

the Hercules, along with Oman and Kuwait.



include Aermacchi’s M311 turbofan

trainer; the only jet in the race;

Embraer’s Super Tucano, Pilatus PC-

21 or the T-6B Texan single turbo-

props. The RJAF has also taken the

novel approach of converting two

Airbus Military CN-235 aircraft into

gunships to support Special

Operations missions. These aircraft

supplement the 18 Boeing AH6 Little

Bird armed reconnaissance helicop-

ters that the RJAF has on order, deliv-

eries of which are expected to com-

mence next year. These aircraft will

support the 28th Group of the Special

Operations Aviation Brigade. Other

notable acquisitions by the RJAF

include two Sikorsky UH-60L

Blackhawk helicopters for VIP work,

and the transfer of eight F-16AM/BM

aircraft from Belgium in July this

year.

KuwaitAlthough the RJAF is not responsi-

ble for Jordan’s ADGE, the Kuwait

Air Force has jurisdiction of this mis-

sion. Like Bahrain, the country is a

member of the Hizam Al-Taawan ini-

tiative (see above) and possesses a

single MIM-23 Hawk battery, plus

ten Oerlikon Contraves/Rheinmetall

Air Defence Skyguard fire control

radar and Selenia/Alenia Aspide

medium-range SAM combinations.

High-altitude air defence is provided

by the air force’s six Patriot batteries,

with Shorts Missile Systems/Thales

Starburst MANPADS affording low-

altitude protection. Kuwait’s Patriot

systems are being upgraded with the

addition of around 80 Lockheed

Martin PAC-3 missiles and the

Guidance Enhanced Missile-Theatre

Ballistic Missile (GEM-T) upgrade to

its existing Patriot missiles. This

accelerates the velocity at which the

missile’s warhead detonates, to

ensure the destruction of ballistic mis-

siles moving at high speeds.

Meanwhile, the Patriot missile sys-

tems’ radar will receive the REP-III

(Radar Enhancement Phase-III)improvement which doubles the

AN/MPQ-53 passive electronically-

scanned array radar’s power thus

improving its surveillance, tracking,

guidance and target discrimination.

Meanwhile, Kuwait’s Aspide missiles

are to be modernised to Spada-2000

configuration improving their day

and night, all-weather capabilities.

Away from the country’s ADGE, the

Kuwaiti Air Force’s fixed-wing fleet

has not been neglected. A single

Boeing C-17 Globemaster-III

freighter is on order which will sup-

plement the three Lockheed Martin

KC-130J cargo and refuelling aircraft

due to enhance the fleet.

OmanWhile Kuwait has elected to pur-

chase Lockheed Martin KC-130J

transport aircraft, Oman is acquiring

‘vanilla’ C-130J and stretched C-

130J-30 freighters. This is only one

part of a wider shopping list of equip-

ment which includes the purchase of NH Industries NH90 Tactical

Transport Helicopters (20 examples),

and new multirole combat aircraft.

Presently, the Royal Air Force of

Oman (RAFO) comprises a mix of 17

SEPECAT Jaguar-S fighter and

ground-attack aircraft, eight F-16C

Block-50+ and four F-16D Block-

52+ jets.

The RAFO is known to be interest-

ed in the acquisition of up to 24

Eurofighter Typhoons, possibly join-

ing Saudi Arabia as the Gulf’s second

operator of the type. In addition, it has

requested information regarding the

possible acquisition of a further 18 F-

16C/D Block-50/52+ jets. Given that

Oman has been a Jaguar operator, it

represents a strong prospect for the

Typhoon’s third export sale beyond

Saudi Arabia and Austria. Nor are the

RAFO’s air defences being neglected.

The force has 28 Rapier SAM sys-tems, associated BAE Systems

Blindfire target tracking and fire con-

trol radar, and S-743D Martello three-

dimensional stacked-beam air search

radar which comprise the country’s

IADS. These capabilities will soon be

supplemented with MBDA VL

MICA short-range/medium-altitude

SAMs.



Erieye (Patria) – Saab’s Erieye airborne early warning and control radar has won two customers

in the Gulf region. The United Arab Emirates is acquiring a single Erieye radar atop of a Saab-

2000 airliner, with Saudi Arabia acquiring two systems.



Qatar and Saudi ArabiaOf all of the Gulf air forces sur-

veyed in this article, it is Qatar’s that

is arguably performing the most mod-

est improvement of its capabilities.

The most notable current acquisition

for the Qatar Emiri Air Force is the

purchase of four C-130J transports.

This is not the case, however, for the

Royal Saudi Air Force (RSAF) which

is pouring investment into the acqui-sition of 72 Typhoon combat aircraft.

These will supplement the 84 Boeing

F-15SA Strike Eagles that the king-

dom is receiving in addition to the

upgrade of the 70 existing F-15s oper-

ated by the RSAF to F-15SA config-

uration. However, it is not only the

fast jet fleet that the RSAF is aug-

menting. Saudi Arabia will be the

destination for up to six Airbus

Military A330 MRTT (MultiRole

Tanker Transport) refuellers, plus a

Saab 2000 ERIEYE Airborne Early

Warning and Control platform.

UAEThe UAE will join the RSAF as an

Erieye operator, as it is acquiring two

of the radar systems mounted onboard

the same number of Saab-340 turbo-

props. The UAE’s airborne surveil-

lance capabilities will be further

enhanced with the delivery of two

Bombardier Dash 8-315 aircraft out-

fitted with Thales’s AMASCOS mar-

itime patrol mission system. Beyond

these intelligence, surveillance and

reconnaissance platforms, the UAE is

strengthening its airlift capabilities

via the acquisition of six C-17s and

twelve C-130Js, with rotary aviation

receiving a similar improvement in

the form eight AgustaWestland

AW139 medium-lift helicopters for

Search-and-Rescue and VIP trans-

port, 40 UH-60M Black Hawks for

the utility and ground attack roles

which will supplement the 30 Boeing

AH-64D Apache Block-III gunships

and 16 Boeing CH-47F Chinook

machines that the country has on

order. The training fleet, meanwhile,

is acquiring 25 Pilatus PC-7s.

Nevertheless, mindful of the threat

presented by Iran, the UAE Air Force

is investing in its ADGE capabilities.

This is occurring via the purchase of

three Lockheed Martin Theatre High-

Altitude Air Defense (THAAD) and

Patriot PAC-3 systems from the

United States, allowing the country to

deploy a domestic anti-tactical ballis-

tic missile capability.

Conclusions

While Iran’s ballistic missile andWMD programmes may be two

strong motivational factors for the air

force modernisations occurring

across the Gulf region, other drivers,

such as the recapitalisation of old

fleets and investment into new capa-

bilities such as fixed-wing gunships,

in Jordan’s case, are pushing this

modernisation forward. While much

of the West still languishes in a slug-

gish economic posture with defence

budgets feeling a similar strain to

education and healthcare spending,

the air forces of the Gulf continue to

require new equipment and capabili-

ties. For the short term at least, the

region will remain attractive to

defence companies across the world.

(*) Strategic Analyst



Rafale – While Oman is a strong export prospect for the Eurofighter Typhoon, the United Arab

Emirates may well emerge as the first export customer for the Dassault Rafale F3. As of

October 2011, France and the UAE were reportedly close to completing a deal to this end.

A330 MRTT (Airbus Military) – The Royal Saudi Air Force looks likely to join the Royal

Australian Air Force as another export customer for Airbus Military’s A330 MRTT tanker. The

Kingdom will receive six of the aircraft.

¯



Today’s turboprops were devel-

oped from the piston engines which



Military Aircrafts Propulsion Systems

On 26th July, Brazilian aircraft builder Embraer announced

plans to perform the maiden flight of its new KC-390 transportaircraft by 2015. The aircraft is remarkable for several reasons. It

represents Brazil’s entry into the military cargo aircraft market; a

sector which has largely been the preserve of European, American,

Russian and Japanese airframe builders since the Second World War.

Importantly, the aircraft also uses a pair of jet powerplants for

propulsion; in this case, two International Aero Engines V2500-E6

turbofans, each producing between 12,246-13,154kgs of thrust. Why is

this engine choice interesting? Put simply, because with the exception

of Boeing’s C-17 Globemaster-III, Antonov’s AN-124 (NATO report-

ing name ‘Condor’), Lockheed Martin’s C-5M Galaxy and

Kawasaki’s C-1 and XC-2 airframes, the KC-390 is unusual in being

a military freighter which uses turbofan propulsion. Furthermore, the

KC-390’s maximum take-off weight is around 81.000kg. This places

the aircraft in the medium-lift category for freighters which also

includes Lockheed Martin’s highly successful C-130 Hercules series,

Antonov’s An-12 family (NATO reporting name ‘Cub’) and

Transport Allianz’s C-160 Transall freighters; all of which use turbo-

prop propulsion.

A400M (Airbus Military) – Airbus Military’s A400M freighter uses a revolutionary engine design in the form of the Europrop TP4000-D6 turboprop.

The engine is the world’s most powerful single rotation turboprop powerplant.

have been used since the dawn of avi-

ation, and the turbojets, which began

to appear on military aircraft during

the Second World War. The turbojet,

invented by British engineer SirFrank Whittle, worked on a simple

principle; fans rotating at the front of

an engine suck in air. The air enters a

compressor where it is presssurized

up to twelve times’ its original pres-

sure. One bi-product of pressurised

air is that it increases in temperature.

While this air is inside the compressor

fuel is added. The pressurised air-fuel

mix is then ignited which takes the

temperature of this mixture to around

704°C. The ignition forces the fuel-

air mixture to expand further as it

heats up, pushing the resulting

exhaust gasses through turbine blades

located in the aft part of the engine.

As the exhaust passes through the tur-

bines and out of the engine, it pro-

duces thrust, pushing the aircraft for-

ward. The exhaust gasses which

rotate the turbine blades also causes





the fan at the front of the engine to

rotate, as both are positioned on the

same axle, causing the fan to suck in

more air and repeat this process.

For the years immediately follow-

ing the Second World War, the turbo-

jet provided an ideal solution for mil-

itary aircraft, particularly for high-

performance jet fighters. However,

continuing research on the turbojet

led to the development of the turbofan

and turboprop. The impetus for the

development of these latter engines

was that turbojets were highly ineffi-

cient as regards fuel consumption,

and were also very noisy. The first

production turbofan, the Rolls-Royce

Conway, was fielded during the

1950s and used on the Handley Page

Victor bomber, along with theVickers VC-10 and Boeing 707-420

airliners. Rolls Royce also pioneered

the development of the turboprop

engine in the form of the RB50 Trent,

which allowed the company to devel-

op the later Dart engine which,

among other aircraft, equipped the

Vickers Viscount medium-range air-

liner. The work that Rolls Royce, and

scores of other companies, would

undertaken ushered in an era of air-

craft propulsion which endured for

the next five decades, and which con-

tinues to persist today.

To appreciate the respective bene-

fits of turboprop and turbofan

engines, it is important to understand

how these power plants work.

Broadly speaking, turboprops and tur-

bofans work in similar, yet different,

ways. As its name suggests, a turbo-

prop uses a propeller mounted on the

front of the engine, in a similar fash-

ion to a piston power plant. An inlet

duct behind the propeller allows air to

enter the engine at high speed. This

high speed air reaches the turboprop’s

compressor which causes the air to

increase in both pressure and temper-

ature.

This air, when it leaves the com-

pressor, has a temperature around

537ºC hotter than when it entered the

engine inlet, and around 30 times

higher in pressure. Fuel is injectedinto this high pressure air, and then

spark plugs ignite the fuel. This

forces the temperature of this gaseous

mix of fuel and air above 1648ºC. The

hot air expands which forces the mix-

ture through turbine blades located at

the rear of the engine. As the mixture

is forced through the turbine blades

positioned on an axle which also

house the compressor blades and the

propeller at the front of the engine

they rotate, causing the compressor

F117 (Pratt and Whitney) – Pratt and Whitney’s F117 series of military turbofan engines are used

on Boeing’s C-17 Globemaster-III freighters and the engine is a development of the PW2000

engine family designed for the Boeing 757 airliner family.

AE2100 (Rolls Royce) – Rolls Royce’s AE2100 turboprop is has sold well and equips a number of

military freighter aircraft including the Alenia C-27J Spartan, the Lockheed Martin C-130J Super

Hercules and the ShinMaywa US-2 amphibious aircraft.



blades and propeller to rotate at the

same time. On passing the turbine

blades the burnt hot mixture leaves

the engine as exhaust. Thus the speed

of the engine, and hence the propeller,

is governed by the amount of fuel

burnt in the pressurised air after it

leaves the compressor. The more fuel

is burnt, the more expansion is expe-

rienced by the hot air, the more air is

forced through the turbine causing the

propeller to rotate at quicker speeds,

making the aircraft thus move faster.

Turbofan engines work in a similar

fashion except the fan, the first part of

the engine, is located in a cowl. The

fan sucks air into the engine which isthen separated into primary air,

around 15 percent of the total inhaled

by the engine, and bypass air which

constitutes the balance of around 85

percent. This bypass air is merely

accelerated by the fan and blown out

of the exhaust of the engine. Yet this

air is not wasted because it has such a

large volume that it produces a huge

amount of thrust in its own right. This

occurs as it is being drawn into the

comparatively small space of the

engine interior, pressurised by the

fan, and then blown out of the rear of

the power plant. This bypass air has

the added benefit of cooling the

engine, and also reducing engine

noise. However, at the same time as

the bypass air is being pressurised and

blown from the engine, the smaller

quantity of primary air hits the

engine’s compressors after being

sucked in through the fan. As the air

travels through the compressor, it

increases noticeably in pressure and

temperature.So which engine is best for a mili-

tary aircraft? The turboprop or the

turbofan? Much depends on the activ-

ity that the aircraft will perform. It

would be a bizarre choice to use a tur-

boprop engine for multirole combat

aircraft which need high speeds to

perform well against hostile war-

planes and to evade enemy ground-

based air defences. That said, a count-

er-insurgency platform which needs

to carry a significant quantity of ord-

nance, remain on station for a pro-

longed period of time and operate in

skies where air superiority is assured

will probably best perform its role

with a turboprop engine.

The philosophy behind engine type

selection and engine choice can be

summed up in the phrase 'horses for

courses'. Essentially, the engine type

selected depends on the role of the

aircraft. This can usually be discerned

at the outset of a procurement process

for a new-build military aircraft. A

Request for Proposals (RFP) willdetail the tasks that the aircraft is

expected to perform be it air-to-

ground attack, air defence, special

missions, or transport and logistics, to

name just four. Other factors will also

be taken into account such as whether

the aircraft needs to have low observ-

able characteristics, the speed and

altitude the plane should be capable

of reaching, and whether it will be

required to perform 'short field' oper-

ations, or flights to and from unpre-

pared strips?

Shawn A. Wilson, who is responsi-

ble for Military Engines

Communications at power plant

builder Pratt and Whitney, says that;

“the key decision for using turboprop

versus turbofan engines is made by

the airframe manufacturer based on

the intended use for the aircraft.

Turboprops are most effective for

short field, short haul applicationswhile turbofans are optimized for

higher altitude and longer flights.”

Mr. Wilson adds that; “turboprops

provide exceptional fuel economy but

are limited to lower, subsonic speeds.

Turbofans provide required thrust at

high subsonic, and even supersonic,

speeds. And for military applications,

turbofans accommodate stealth fea-



V2500-E6 turbofan engine, produce between 12,246-13,154kgs of thrust.



tures much more readily.” To this

end, Pratt and Whitney has earned a

global reputation for providing high

performance turbofan engines for

military aircraft. These include the

F100 power plants which equip the

General Dynamics/Lockheed Martin

F-16 Viper family and McDonnell

Douglas/Boeing F-15 Eagle family of

multirole combat aircraft. Meanwhile

the firm's F117 engine series power

Boeing's C-17 Globemaster-III

freighters, with the F119 and F135

engines equipping the Lockheed

Martin F-22A Raptor and F-35

Lightning-II Joint Strike Fighter.

The importance of realising thetrade off between turbofan and turbo-

prop engines is echoed by Nick

Britton, External Communications

Manager for Defence at Rolls Royce

PLC. One important advantage that a

turboprop confers, Mr. Britton

argues, is good performance during a

steep descent rate; something which

is noticeably valuable when an air-

craft is performing a tactical landing

in an environment which may contain

significant threats in the form of

ground-based air defences. Although

ultimately he argues that engine

choice; “depends on the mission pro-

files that you require. For example,

the fuel efficiency that you can derive

from a turboprop can enable you to

carry a greater payload or more range,

or more loiter time if you are on a sur-

veillance mission.” Moreover, mili-

tary cargo aircraft regularly operate

from, and fly into, sparsely-equippedairstrips and, “a turboprop will be

more efficient and more resilient in

some of the harsh operating environ-

ments, such as unprepared landing

strips.” This raises an important issue

regarding the selection of a turbofan

engine to equip an aircraft such as a

military freighter as a; “turbofan-

powered aircraft will require a greater

fuel load and would probably need to

operate from a paved surface.”

Rolls Royce is heavily involved in

both the military turboprop and turbo-

fan worlds. Mr. Britton adds that the

performance gap between turboprop

and turbofan engines is diminishing,

citing the TP400 power plant that

equips the Airbus Military A400M

freighter as an example: “A turbofan

is generally quieter than a turboprop,

and permits speeds up to Mach 0.85,

but the airspeed of today's advanced

turboprops are nearing that of turbo-

fan performance. The A400M, for

example, is able to operate at Mach

0.72.”Although turboprop and turbofan

engines have been in service for

decades, their respective designs are

still very much a work in progress.

Shawn A. Wilson says that his com-

pany sees; “fuel efficiency improve-

ments for these engines,” adding that

Pratt and Whitney; “also will use

higher technology thermal barrier

coatings plus materials with better

thermal barrier characteristics which

will contribute to fuel savings, and

better durability of engine parts.” As

Mr. Wilson’s comments show, design

efforts for all military aircraft engine

designers will not remain static over

the coming years as companies work

to hone and improve their engine

designs still further. There is unlikely

to be any absolute panacea as far as

military aircraft propulsion systems

are concerned. The idea that the bestengine for the job should always be

selected, regardless of whether it is a

turboprop or turbofan design, is like-

ly to persist for some time yet.

T.W.


F135 engine equippe the Lockheed Martin F-22A Raptor and F-35 Lightning-II Joint Strike

Fighter.

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Documents

Defence 21 Magazine,English Supplement,Issue-45.pdf