STEALTH TECHNOLOGY IN NAVAL WARFARE

A

Seminar Report

Submitted

in partial fulfillment

for the award of the Degree of

Bachelor of Technology

in Department of Mechanical Engineering

Supervisor Submitted By:

Dr. Manu Augustine Siddharth Bhatnagar

(Reader) (12ESKME417)

Department of Mechanical Engineering

Swami Keshvanand Institute of Technology,

Management & Gramothan Rajasthan Technical University

May, 2016

i

Candidate’s Declaration

I hereby declare that the Seminar Report entitled Stealth Technology in Naval Warfare

is being submitted in partial fulfillment for the award of Degree of “Bachelor of

Technology” in Thermal Engineering. It is being submitted to the Department of

Mechanical of Engineering, Swami Keshvanand Institute of Technology,

Management & Gramothan, Rajasthan Technical University is compiled and prepared

by me under the supervision and guidance of Dr. Manu Augustine.

Siddharth Bhatnagar

Roll No. 12ESKME417

ii

ACKNOWLEDGMENT

A research work owes its success from commencement to completion, to the people in love

with researches at various stages. It comes out to be a great pleasure and experience to us to

have seminar report for the fulfillment in the Bachelor of Technology. I would express

appreciation to all who assisted me in one another way.

I feel immense pleasure in conveying heartiest thanks a deep sense of gratitude to Dr. N.K.

Banthiya, (Head of Mechanical Engineering Department), Dr. S.L. Surana (Director of

Academics), and Dr. S.K. Kalla (Principal), Swami Keshvanand Institute of Technology

Management &Gramothan, Jaipur for their efforts and for technical as well as moral support.

I feel indebted to express our heartiest thanks and gratitude to Dr. Manu Augustine , Lecturer

of Department of Mechanical Engineering of Swami Keshvanand Institute of Technology

Management &Gramothan, Jaipur for their valuable time leaned guidance illuminating during

seminar .

I would like to thank Ms. Sarita Choudhary (Reader) and Mr. Dinesh Kumar Sharma (Sr.

Lecturer) for their valuable help throughout the work for boosting me for creative thinking

and helping me to think practically.

Siddharth Bhatnagar

B.Tech. IV Year

(Mechanical Engineering)

iii

ABSTRACT

Stealth technology also termed LO technology (low observable technology) is a sub-

discipline of military tactics and passive electronic countermeasures, which cover a range of

techniques used with personnel, aircraft, ships, submarines, missiles and satellites to make

them less visible (ideally invisible) to radar, infrared, sonar and other detection methods. It

corresponds to military camouflage for these parts of the electromagnetic spectrum (Multi-

spectral camouflage).

Development of modern stealth technologies in the United States began in 1958, where

earlier attempts in preventing radar tracking of its U-2 spy planes during the Cold War by the

Soviet Union had been unsuccessful. Designers turned to develop a particular shape for

planes that tended to reduce detection, by redirecting electromagnetic waves from radars.

Radar-absorbent material was also tested and made to reduce or block radar signals that

reflect off from the surface of planes. Such changes to shape and surface composition form

stealth technology as currently used on the Northrop Grumman B-2 Spirit "Stealth Bomber".

The concept of stealth is to operate or hide without giving enemy forces any indications as to

the presence of friendly forces. This concept was first explored through camouflage by

blending into the background visual clutter. As the potency of detection and interception

technologies (radar, Infra-red search and track, surface-to-air missiles, etc.) have increased

over time, so too has the extent to which the design and operation of military personnel and

vehicles have been affected in response. Some military uniforms are treated with chemicals to

reduce their infrared signature. A modern "stealth" vehicle is designed from the outset to

have a chosen spectral signature. The degree of stealth embodied in a particular design is

chosen according to the predicted capabilities of projected threats.

iv

CONTENTS

Certificate ..................................................................................................................................i

Acknowledgement.................................................................................................................... ii

Abstract.................................................................................................................................... iii

List of Figures ….......................................................................................................................v

Chapter 1: Introduction ….........................................................................................................1

1.1 Background of Stealth Technology ……………………...…..............................................2

Chapter 2: Literature Survey……..............................................................................................4

2.1 Stealth Technology in Modern Era………….….................................................................4

2.1.1 Low Frequency RADAR…...............................................................................................4

2.1.2Multiple Emitter.................................................................................................................5

2.1.3 Ship Wakes and Spray …..................................................................................................5

2.1.4 Schlieren Signature …......................................................................................................5

Chapter 3: What is Stealth? …...................................................................................................6

3.1 RADAR Cross Section Reduction …..................................................................................7

3.2 Shape of Ships ….................................................................................................................7

3.3 General Design….................................................................................................................8

3.4 Material …...........................................................................................................................8

3.4.1 Non Metallic Frame ….....................................................................................................8

3.4.2 Radiation Absorbing Material …......................................................................................8

3.5 Reducing RF Emissions …..................................................................................................9

3.6 Tactics ….............................................................................................................................9

Chapter 4: How to Counter Stealth ….....................................................................................10

4.1 Limitations …....................................................................................................................10

4.1.1 Instability in Design …...................................................................................................10

4.1.2 Aerodynamic Conditions …............................................................................................10

4.1.3 Electromagnetic Emission …..........................................................................................11

4.1.4 Vulnerable mode of operation …....................................................................................11

4.1.5 Reduced Payload….........................................................................................................12

4.1.6 Sensitive Skin ….............................................................................................................12

4.1.7 Cost of Operation ….......................................................................................................12

Chapter 5: Conclusions ….......................................................................................................13

5.1 Future of Stealth Technology …........................................................................................14

5.2 Advantages and Applications …........................................................................................14

5.3 Disadvantages of Stealth Technology …...........................................................................15

References ….....................................................................................................................15

v

LIST OF FIGURES

Fig. 2.1 Vehicle Shape and RAM Coating …........................................................................................5

Fig. 3.1 Deflection due to sharp edges …..............................................................................................6

Fig. 3.2 Deflection due to angular design ….........................................................................................7

Fig. 3.3 Clean and Angular Design …...................................................................................................7

Fig. 4.1 Payload Delivery …................................................................................................................12

Fig. 5.1 Sea Shadow 529 ….................................................................................................................14

Fig. 5.2 INS Shivalik ….......................................................................................................................14

1

Chapter 1

Introduction

Stealth vehicles are designed to avoid detection using a variety of technologies that reduce

reflection/emission of radar, infrared, visible light, radio-frequency (RF) spectrum, and audio,

collectively known as stealth technology.[1] Development of stealth technology likely began

in Germany during World War II, the prototyped Horton was designed for twin BMW 003 jet

engines but finally powered by twin Junkers Jumbo 004 jet engines being described as the

first stealth vehicle. Well-known modern examples of stealth of U.S. vehicles include the

United States' F-117 Nighthawk (1981–2008), the B-2 Spirit, the F-22 Raptor, and the F-35

Lightning II.

While no vehicle is totally invisible to radar, stealth vehicle make it more difficult for

conventional radar to detect or track the vehicle effectively, increasing the odds of an vehicle

successfully avoiding detection by enemy radar and/or avoiding being successfully targeted

by radar guided weapons. Stealth is the combination of passive low observable (LO) features

and active emitters such as Low Probability of Intercept Radars, radios and laser designators.

These are usually combined with active measures such as carefully planning all mission

manoeuvres in order to minimize the vehicle's radar cross section, since common actions

such as hard turns or opening bomb bay doors can more than double an otherwise stealthy

vehicle's radar return. It is accomplished by using a complex design philosophy to reduce the

ability of an opponent's sensors to detect, track, or attack the stealth vehicle.[2] This

philosophy also takes into account the heat, sound, and other emissions of the vehicle as these

can also be used to locate it.

Full-size stealth combat ships and submarines demonstrators have been flown by the United

States (in 1977), Russia (in 2010) and China (in 2011). The U.S. military has adopted three

stealth designs, and is preparing to adopt the Lockheed Martin F-35 Lightning II.

Most recent fighter designs will claim to have some sort of stealth, low observable, reduced

RCS or radar-jamming capability, but there has been no direct combat experience against

stealth ships.

2

1.1 Background of Stealth Technology

The concept of camouflage is known to predate warfare itself. Hunters have been using

vegetation to conceal themselves perhaps as long as people have been hunting. In England,

irregular units of gamekeepers in the 17th century were the first to adopt drab colors

(common in 16th century Irish units) as a form of camouflage, following examples from the

continent.

During World War I, the Germans experimented with the use of Cellon (Cellulose acetate), a

transparent covering material, in an attempt to reduce the visibility of military vehicle. Single

examples of the Fokker E.III Eindecker fighter monoplane, the Albatros C.I two-seat

observation biplane, and the prototype heavy bomber were covered with Cellon. In fact,

sunlight glinting from the material made the vehicle even more visible. Celon was also found

to be quickly degraded both by sunlight and in-flight temperature changes so the attempt to

make transparent vehicle was not proceeded with.

In 1916, the British modified a small SS class airship for the purpose of night-time

reconnaissance over German lines on the Western Front. Fitted with a silenced engine and a

black gas bag, the craft was both invisible and inaudible from the ground but several night-

time flights over German-held territory produced little useful intelligence and the idea was

dropped.

Diffused lighting camouflage, a ship borne form of counter-illumination camouflage, was

trialled by the Royal Canadian Navy from 1941 to 1943. The concept was followed up, but

for vehicle, by the Americans and the British: in 1945 a Grumman Avenger with Yehudi

lights, reached 3,000 yards (2,700 m) from a ship before being sighted. This ability was

rendered obsolete by radar.[3]

The U-boat U-480 may have been the first stealth submarine. It featured an anechoic tile

rubber coating, one layer of which contained circular air pockets to defeat ASDIC sonar.

Radar absorbent rubber/semiconductor composite paints and materials (codenames: "Sumpf",

"Schornsteinfeger") were used by the Kriegsmarine on submarines in World War II. Tests

showed they were effective in reducing radar signatures at both short (centimetres) and long

(1.5 metre) wavelengths.

3

In 1960, the first stealth technology development program was initiated by USAF, by

reducing the radar-cross-section of a Ryan Q-2C Firebee drone. This was achieved through

specially designed screens over the air intake, radar-absorbent material on the fuselage and a

special radar-absorbing paint.[4]

In 1958, the U.S. Central Intelligence Agency requested funding for a reconnaissance vehicle

to replace the existing U-2 spy planes,[5] and Lockheed secured contractual rights to produce

it.[6] "Kelly" Johnson and his team at Lockheed's Skunk Works were assigned to produce the

A-12 (or OXCART), the first of the previously top secret Blackbird series, which operated at

high altitude of 70,000 to 80,000 ft and speed of Mach 3.2 to avoid radar detection. Radar

absorbent material was used on U-2 spy planes, and various plane shapes designed to reduce

radar detection were developed in earlier prototypes, named A1 to A11. In 1964, an optimal

plane shape taking into account compactness was developed for another "Blackbird", the

Lockheed SR-71. This vehicle surpassed prior models in both altitude (90,000 ft) and speed

(Mach 3.3). The SR-71 included a number of stealthy features, notably its canted vertical

stabilizers, the use of composite materials in key locations, and the overall finish in radar

absorbing paint.

During the 1970s the U.S. Department of Defence launched project Lockheed Have Blue,

with the aim of developing a stealth fighter. There was fierce bidding between Lockheed and

Northrop to secure the multibillion-dollar contract. Lockheed incorporated into its bid a text

written by the Soviet/Russian physicist Pyotr Ufimtsev from 1962, titled Method of Edge

Waves in the Physical Theory of Diffraction, Soviet Radio, Moscow, 1962. In 1971 this book

was translated into English with the same title by U.S. Air Force, Foreign Technology

Division.

The theory played a critical role in the design of American stealth-vehicle F-117 and B-2.

Equations outlined in the paper quantified how a plane's shape would affect its detect ability

by radar, its radar cross-section (RCS). This was applied by Lockheed in computer simulation

to design a novel shape they called the "Hopeless Diamond", wordplay on the Hope

Diamond, securing contractual rights to produce the F-117 Nighthawk starting in 1975. In

1977 Lockheed produced two 60% scale models under the Have Blue contract. They Have

Blue program was a stealth technology demonstrator that lasted from 1976 to 1979. The

success of Have Blue led the Air Force to create the Senior Trend program which developed

the F-117.

4

Chapter 2

Literature Survey

2.1 Stealth Technology in Modern Era

Modern stealth vehicle first became possible when Denys Overholser, a mathematician

working for Lockheed Vehicle during the 1970s, adopted a mathematical model developed

by Petr Ufimtsev, a Soviet scientist, to develop a computer program called Echo 1. Echo

made it possible to predict the radar signature of an vehicle made with flat panels, called

facets. In 1975, engineers at Lockheed Skunk Works found that an vehicle made with faceted

surfaces could have a very low radar signature because the surfaces would radiate almost all

of the radar energy away from the receiver. Lockheed built a model called "the Hopeless

Diamond", a reference to the famous Hope Diamond and the design's predicted instability.

Because advanced computers were available to control the flight of even a Hopeless

Diamond, for the first time designers realized that it might be possible to make an vehicle that

was virtually invisible to radar.

Reduced radar cross section is only one of five factors the designers addressed to create a

truly stealthy design such as the F-22. The F-22 has also been designed to disguise its

infrared emissions to make it harder to detect by infrared homing ("heat seeking") surface-to-

air or air-to-air missiles. Designers also addressed making the vehicle less visible to the

naked eye, controlling radio transmissions, and noise abatement.

The first combat use of purpose-designed stealth vehicle was in December 1989 during

Operation Just Cause in Panama. On 20 December 1989, two United States Air Force F-117s

bombed a Panamanian Defence Force barracks in Rio Hato, Panama. In 1991, F-117s were

tasked with attacking the most heavily fortified targets in Iraq in the opening phase of

Operation Desert Storm and were the only jets allowed to operate inside Baghdad's city

limits.

2.1.1 Low-frequency radar

Shaping offers far fewer stealth advantages against low-frequency radar. If the radar

wavelength is roughly twice the size of the target, a half-wave resonance effect can still

generate a significant return. However, low-frequency radar is limited by lack of available

frequencies (many are heavily used by other systems), by lack of accuracy of the diffraction-

limited systems given their long wavelengths, and by the radar's size, making it difficult to

5

transport. A long-wave radar may detect a target and roughly locate it, but not provide

enough information to identify it, target it with weapons, or even to guide a fighter to it.

Noise poses another problem, but that can be efficiently addressed using modern computer

technology; Chinese "Nantsin" radar and many older Soviet-made long-range radars have

been modified by supporting them with modern computers.

2.1.2 Multiple emitters

Much of the stealth comes in in directions different than a direct return. Thus, detection can

be better achieved if emitters are separate from receivers. One emitter separate from one

receiver is termed bistatic radar; one or more emitters separate from more than one receiver is

termed multistatic radar. Proposals exist to use reflections from emitters such as civilian radio

transmitters, including cellular telephone radio towers.

2.1.3 Ship's wakes and spray

Synthetic Aperture side scan radars can be used to detect the location and heading of ships

from their wake patterns. These may be detectable from orbit. When a ship moves through a

seaway it throws up a cloud of spray which can be detected by radar.

2.1.4 Schlieren signature

Anything that disturbs the atmosphere may be detected (Schlieren photography) because of

the Schlieren effect caused by that atmospheric disturbance. This type of Measurement and

signature intelligence detection falls under the category of Electro-optical MASINT.

Fig.2.1: Vehicle Shape and RAM Coating.

6

Chapter 3

What is Stealth and how it works in Naval Applications?

The goal of stealth technology is to make an vehicle invisible to radar. There are two

different ways to create invisibility:

• The vehicle can be shaped so that any radar signals it reflects are reflected away from

the radar equipment.

• The vehicle can be covered in materials that absorb radar signals.

Most conventional vehicle have a rounded shape. This shape makes them aerodynamic,

but it also creates a very efficient radar reflector. The round shape means that no matter

where the radar signal hits the plane, some of the signal gets reflected back:

A stealth vehicle, on the other hand, is made up of completely flat surfaces and very sharp

edges. When a radar signal hits a stealth plane, the signal reflects away at an angle, like this:

In addition, surfaces on a stealth vehicle can be treated so they absorb radar energy as

well. The overall result is that a stealth vehicle like an F-117A can have the radar signature of

a small bird rather than a vehicle. The only exception is when the plane banks – there will

often be a moment when one of the panels of the plane will perfectly reflect a burst of radar

energy back to the antenna.

Fig.3.1: Deflection due to Sharp Edges.

7

3.1 RADAR Cross Section Reductions

Almost since the invention of radar, various methods have been tried to minimize detection.

Rapid development of radar during World War II led to equally rapid development of

numerous counter radar measures during the period; a notable example of this was the use of

chaff. Modern methods include Radar jamming and deception.

Increased awareness of stealth vehicles and the technologies behind them is prompting the

development of means to detect stealth vehicles, such as passive radar arrays and low-

frequency radars. Many countries nevertheless continue to develop low-RCS vehicles

because they offer advantages in detection range reduction and amplify the effectiveness of

on-board systems against active radar homing threats.

Fig. 3.2: Deflection due to Angular Design.

3.2 Shape of Ships

Ships have also adopted similar methods. Though the earlier Arleigh Burke-class destroyer

incorporated some signature-reduction features, the Skjold-class corvette was the first coastal

defence and the French La Fayette-class frigate the first ocean-going stealth ship to enter

service. Other examples are the German Sachsen-class frigates, the Swedish Visby-class

corvette, the USS San Antonio amphibious transport dock, and most modern warship designs.

Fig.3.3: Clean and Angular Design of a Ship.

8

3.3 General Design

The general design of a stealth vehicle is always aimed at reducing radar and thermal

detection. It is the designer’s top priority to satisfy the following conditions, which ultimately

decide the success of the vehicle:-

• Reducing thermal emission from thrust

• Reducing radar detection by altering some general configuration (like introducing the

split rudder)

• Reducing radar detection when the vehicle opens its weapons bay

• Reducing infra-red and radar detection during adverse weather conditions

3.4 Materials

3.4.1 Non-metallic Frame

Dielectric composites are more transparent to radar, whereas electrically conductive materials

such as metals and carbon fibres reflect electromagnetic energy incident on the material’s

surface. Composites may also contain ferrites to optimize the dielectric and magnetic

properties of a material for its application.

3.4.2 Radar-absorbing material

Radar-absorbent material (RAM), often as paints, is used especially on the edges of metal

surfaces. While the material and thickness of RAM coatings can vary, the way they work is

the same: absorb radiated energy from a ground or air based radar station into the coating and

converts it to heat rather than reflect it back. Current technologies include dielectric

composites and metal fibres containing ferrite isotopes. Paint comprises depositing pyramid

like colonies on the reflecting superficies with the gaps filled with ferrite-based RAM. The

pyramidal structure deflects the incident radar energy in the maze of RAM. A commonly

used material is known as “Iron Ball Paint‟.[7] Iron ball paint contains microscopic iron

spheres that resonate in tune with incoming radio waves and dissipate the majority of their

energy as heat, leaving little to bounce back to detectors. FSS are planar periodic structures

that behave like filters to electromagnetic energy. The considered frequency selective

surfaces are composed of conducting patch elements pasted on the ferrite layer. FSS are used

for filtration and microwave absorption.

9

3.5 Reducing Radio Frequency (RF) Emissions

In addition to reducing infrared and acoustic emissions, a stealth vehicle must avoid radiating

any other detectable energy, such as from on-board radars, communications systems, or RF

leakage from electronics enclosures. The F-117 uses passive infrared and low light level

television sensor systems to aim its weapons and the F-22 Raptor has advanced LPI radar

which can illuminate enemy vehicle without triggering a radar warning receiver response.

3.6 Tactics

Stealthy strike vehicle such as the Lockheed F-117 Nighthawk, designed by the famous

Skunk Works, are usually used against heavily defended enemy sites such as Command and

control centres or surface-to-air missile (SAM) batteries. Enemy radar will cover the airspace

around these sites with overlapping coverage, making undetected entry by conventional

vehicle nearly impossible. Stealthy vehicle can also be detected, but only at short ranges

around the radars; for a stealthy vehicle there are substantial gaps in the radar coverage. Thus

a stealthy vehicle flying an appropriate route can remain undetected by radar. Many ground-

based types of radar exploit Doppler filter to improve sensitivity to objects having a radial

velocity component with respect to the radar. Mission planners use their knowledge of enemy

radar locations and the RCS pattern of the vehicle to design a flight path that minimizes radial

speed while presenting the lowest-RCS aspects of the vehicle to the threat radar. To be able

to fly these “safe” routes, it is necessary to understand an enemy’s radar coverage (see

electronic intelligence). Airborne or mobile radar systems such as AWACS can complicate

tactical strategy for stealth operation.

10

Chapter 4

How to counter Stealth Technology?

Whenever a technology is developed for military purposes, another technology is also

developed to counter that technology. There are strong efforts to develop a system that can

counter the low observability of the fifth generation stealth vehicle. There are ways of

detection and elimination of a low observable vehicle but this doesn’t give a 100% success

rate at present.

On a radar screen, vehicle will have their radar cross sections with respect to their size. This

helps the radar to identify that the radar contact it has made is an vehicle. Conventional

vehicle are visible on the radar screen because of its relative size. On the other hand, the

relative size of a stealth vehicle on the radar screen will be that of a large bird. This is how

stealth vehicle are ignored by radar and thus detection is avoided. A proven method to detect

and destroy stealth vehicle is to triangulate its location with a network of radar systems. This

was done while the F-117 was shot down during the NATO offensive over Yugoslavia.

A new method of detecting low observable vehicle is just over the horizon. Scientists have

found a method to detect stealth vehicle with the help of microwaves similar to the ones

emitted by the cell phone towers. Nothing much is known about this technology, but the US

military seems to be very keen about doing more research on this.

4.1 Limitations

4.1.1 Instability of design

Early stealth vehicle were designed with a focus on minimal radar cross section (RCS) rather

than aerodynamic performance. Highly-stealth vehicle like the F-117 Nighthawk are

aerodynamically unstable in all three axes and require constant flight corrections from a fly-

by-wire (FBW) flight system to maintain controlled flight. As for the B-2 Spirit, which was

based on the development of the flying wing vehicle by Jack Northrop in 1940, this design

allowed for a stable vehicle with sufficient yaw control, even without vertical surfaces such

as rudders.

4.1.2 Aerodynamic limitations

Earlier stealth vehicle (such as the F-117 and B-2) lack afterburners, because the hot exhaust

would increase their infrared footprint, and flying faster than the speed of sound would

produce an obvious sonic boom, as well as surface heating of the vehicle skin which also

increases the infrared footprint. As a result, their performance in air combat manoeuvring

11

required in a dogfight would never match that of a dedicated fighter vehicle. This was

unimportant in the case of these two vehicle since both were designed to be bombers. More

recent design techniques allow for stealthy designs such as the F-22 without compromising

aerodynamic performance. Newer stealth vehicle, like the F-22, F-35 and the Sukhoi T-50,

have performance characteristics that meet or exceed those of current front-line jet fighters

due to advances in other technologies such as flight control systems, engines, airframe

construction and materials.

4.1.3 Electromagnetic emissions

The high level of computerization and large amount of electronic equipment found inside

stealth vehicle are often claimed to make them vulnerable to passive detection. This is highly

unlikely and certainly systems such as Tamara and Kolchuga, which are often described as

counter-stealth radars, are not designed to detect stray electromagnetic fields of this type.

Such systems are designed to detect intentional, higher power emissions such as radar and

communication signals. Stealth vehicle are deliberately operated to avoid or reduce such

emissions.

Current Radar Warning Receivers look for the regular pings of energy from mechanically

swept radars while fifth generation jet fighters use Low Probability of Intercept Radars with

no regular repeat pattern.

4.1.4 Vulnerable modes of Operation

Stealth Vehicles are still vulnerable to detection during, and immediately after using their

weaponry. Since stealth payload (reduced RCS bombs and cruise missiles) are not yet

generally available, and ordnance mount points create a significant radar return, stealth

vehicle carry all armaments internally. As soon as weapons bay doors are opened, the plane’s

RCS will be multiplied and even older generation radar systems will be able to locate the

stealth vehicle. While the vehicle will reacquire its stealth as soon as the bay doors are closed,

a fast response defensive weapons system has a short opportunity to engage the vehicle.

This vulnerability is addressed by operating in a manner that reduces the risk and

consequences of temporary acquisition. The B-2’s operational altitude imposes a flight time

for defensive weapons that makes it virtually impossible to engage the vehicle during its

weapons deployment. New stealth vehicle designs such as the F-22 and F-35 can open their

bays, release munitions and return to stealthy flight in less than a second.

Also, such vehicle as the F-22 Raptor and F-35 Lightning II Joint Strike Fighter can also

carry additional weapons and fuel on hard points below their wings. When operating in this

mode the planes will not be nearly as stealthy, as the hard points and the weapons mounted

on those hard points will show up on radar systems. This option therefore represents a trade-

off between stealth or range and payload. External stores allow those vehicle to attack more

12

targets further away, but will not allow for stealth during that mission as compared to a

shorter range mission flying on just internal fuel and using only the more limited space of the

internal weapon bays for armaments.

4.1.5 Reduced Payload

Fully stealth vehicle carry all fuel and armament internally, which limits the payload. By way

of comparison, the F-117 carries only two laser or GPS guided bombs, while a non-stealth

attack vehicle can carry several times more. This requires the deployment of additional

vehicle to engage targets that would normally require a single non-stealth attack vehicle. This

apparent disadvantage however is offset by the reduction in fewer supporting vehicle that are

required to provide air cover, air-defence suppression and electronic counter measures,

making stealth vehicle “force multipliers”.

Fig.4.1: Payload Delivery.

4.1.6 Sensitive skin

Stealth vehicles often have skins made with Radar-absorbent materials or RAMs. Some of

these contain Carbon black particles, some contain tiny iron spheres. There are many

materials used in RAMs, and some are classified, particularly the materials that specific

vehicle use.

4.1.7 Cost of operations

Stealth vehicles are typically more expensive to develop and manufacture. An example is the

B-2 Spirit that is many times more expensive to manufacture and support than conventional

bomber vehicle. The B-2 program cost the U.S. Air Force almost $105 billion.

13

Chapter 5

Conclusions

Stealth technology is a concept that is not at all new. During the Second World War, allied

vehicle used tin and aluminium foils in huge numbers to confuse German radar installations.

This acted as a cover for allied bombers to conduct air raids. This method was later used as

chaffs by vehicles to dodge radar guided missiles. The first stealth vehicle was the F-117

developed by Lockheed Martin. It was a top-secret project developed by its Skunk Works

unit. The F-117 was only revealed during the late 80s and then saw action in the Persian Gulf.

In due course of time the B-2 was developed as a successor to the B-2. Though both of them

serve different purposes, the B-2 went a step ahead of the F-117. The B-2 was developed to

deliver nuclear weapons and other guided and unguided bombs. On the other hand the F-117

was developed to deliver its precision laser guided bombs. Another stealth vehicle, which

made a lot of promises and in the end ended up in a trashcan, was the A-12. It was a fighter

that was designed to replace the F-14 and F-18 in the future. The capabilities of this vehicle

were boasted to such an extent that the project ended up in a big mess. Billions of dollars

were wasted for nothing.

Stealth technology became famous with the ATF contest. The Boeing-Lockheed YF-22 and

the McDonell Douglas-Grumman YF-23 fought for the multi-billion contract to build the

fighter that would take the USAF into the fifth generation fighter era. The Boeing-Lockheed

won the contract and the F-22 was approved to be the replacement for the F-15 "Eagle"

interceptor

America now has a competitors, Russia decided to respond to the development of the F-22 by

making the Su-47 (S-37) "Berkut" and the MiG-35 "Super Fulcrum / Raptor Killer". These

fighters were developed by the two leading aviation firms in Russia Sukhoi and Mikhoyan

Gurevich (MiG). The future of these projects totally depends on the funding which will be

provided to the Russian defence sector. This time Boeing developed the X-32 and the

Lockheed it’s X-35. With the experience gained from developing the F-22, they were tasked

with making a replacement for the F-16. This saw great technological advances, as they had

to make the first operational supersonic VSOL vehicle. Lockheed martin took the technical

assistance of Russian scientists who developed the Yak-141. The Yak-141 is the first

supersonic VSTOL vehicle. In the end 11 the Lockheed team with its X-35 won the contract

and the fighter was re-designated as the F-35.

Many projects remain over the horizon that will use stealth technology as its primary

capability. They come from some of the most unlikely contenders. These projects include the

Euro JSF, which will be designed by the team that developed the EF-2000. Russia is stepping

forward with its LFS project with the S-54 and other designs. Two new entries into this field

will be India and China. India will be introducing its MCA, which is a twin engine fighter

without vertical stabilizers. This fighter will use thrust vectoring instead of rudders. China

will be introducing the J-12 (F-12/XXJ) which is equivalent to US fighter F-22.

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Fig.5.1: Sea Shadow 529 (USA)

Fig.5.2: INS Shivalik (India)

5.1 Future of Stealth Technology

Stealth technology is clearly the future of air combat. In the future, as air defence systems

grow more accurate and deadly, stealth technology can be a factor for a decisive by a country

over the other. In the future, stealth technology will not only be incorporated in fighters and

bombers but also in ships, helicopters, tanks and transport planes. These are evident from the

RAH-66 "Comanche" and the Sea Shadow stealth ship, Sea Shadow (IX-529) is an

experimental stealth ship built by Lockheed for the United States Navy to determine how a

low radar profile might be achieved and to test high stability full configurations which have

been used in 12 oceanographic ships.

Ever since the Wright brothers flew the first powered flight, the advancements in this

particular field of technology have seen staggering heights. Stealth technology is just one of

the advancements that we have seen. In due course of time we can see many improvements in

the field of military aviation which would one-day even make stealth technology obsolete.

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5.2 Advantages and Applications

The benefits of stealth apply not only to platforms but to a lot of weapons as well. Anti-

surface munitions like the JSOW, JASSM, Apache/SCALP/Storm Shadow, Taurus/KEPD

and many others are specifically shaped and treated to minimize their radar and IR signatures.

This has two useful payoffs: On the one hand, the weapon itself becomes less vulnerable to

enemy defensive systems, which means that fewer of the weapons launched will be shot

down before reaching their target(s). This in turn means that fewer weapons and their parent

platforms need to be allocated to any given mission, and finally the end result is that a greater

number of targets can be confidently engaged with a given force. The other benefit is the

advantage of surprise and its effect in cases where shrinking the enemies available reaction

time is of the essence. A good example of such a situation is a typical OCA strike against an

airfield. If non stealthy strike vehicle or stand-off weapons are used, it is quite likely that they

will be detected far enough out that the enemy will have some time available (even just 4-5

mins will do) to gets many of his ready-to-fly vehicle in the air and fly them somewhere else

to preserve them. If the vehicle being flushed include armed hot-pad alert fighters (a common

protective measure) these can immediately and actively contribute to the base defence against

the incoming attack. Contrast this with a situation where, as a result of using stealthy

weapons and/or platforms, the base is caught virtually napping and the attack is detected so

perilously close that the enemy Has no time to get anything in the air but instead can only

rely on his ground-based terminal defences. This can mean the difference between the base

suffering little or no damage and being virtually obliterated.

5.3 Disadvantages of Stealth Technology

Stealth technology has its own disadvantages like other technologies. Stealth vehicle cannot

fly as fast or is not maneuverable like conventional vehicle. The F-22 and the vehicle of its

category proved this wrong up to an extent. Though the F-22 may be fast or maneuverable, it

can't go beyond Mach 2 and cannot make turns like the Su-37. Another serious disadvantage

with the stealth vehicle is the reduced amount of payload it can carry. As most of the payload

is carried internally in a stealth vehicle to reduce the 10 radar signature, weapons can only

occupy a less amount of space internally. On the other hand a conventional vehicle can carry

much more payload than any stealth vehicle of its class

Whatever may be the disadvantage a stealth vehicle can have, the biggest of all disadvantages

that it faces is its sheer cost. Stealth vehicle literally costs its weight in gold. Fighters in

service and in development for the USAF like the B-2 ($2 billion), F-117 ($70 million) and

the F-22 ($100 million) are the costliest planes in the world. After the cold war, the number

of B-2 bombers was reduced sharply because of its staggering price tag and maintenance

charges. There is a possible solution for this problem. In the recent past the Russian design

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firms Sukhoi and Mikhoyan Gurevich (MiG) have developed fighters which will have a price

tag similar to that of the Su-30MKI. This can be a positive step to make stealth technology

affordable for third world countries.

References

[1] Rao G.A., Mahulikar S.P. (2002). "Integrated review of stealth technology and its role in

airpower". Aeronautical Journal 106 (1066): 629–641.

[2] Richelson, J.T. (10 September 2001). "Science, Technology and the CIA". The National

Security Archive. The George Washington University. Retrieved 6 October 2009.

[3] Cadirci, S. "RF Stealth (or Low Observable) and Counter- RF Stealth Technologies:

Implications of Counter- RF Stealth Solutions for Turkish Air Force." Naval Postgraduate

School, Monterey California, Ph.D. Thesis. March 2009. Accessed 6 October 2009

[4] Haddow, G.W.; Peter M. Grosz (1988). The German Giants - The German R-Planes

1914-1918 (3rd ed.). London: Putnam. ISBN 0-85177-812-7.

[5] Hepcke, Gerhard (2007). "The Radar War, 1930-1945" (PDF). English translation by

Hannah Liebmann. Radar World: 45. Retrieved 19 September 2012.

[6] Knott, Eugene; Shaeffer, John; Tuley, Michael (1993). Radar Cross Section, 2nd ed.

Artech House, Inc. p. 231. ISBN 0-89006-618-3.

[7] Sweetman, Bill. "The Bomber that radar cannot see." New Scientist, 4 March 1982.