This document provides an overview of stealth technology in naval warfare. It discusses how stealth technology began with attempts in World War II to reduce detection of aircraft and submarines. Modern stealth technologies aim to reduce detection by radar, infrared, sonar and other sensors. Key aspects of naval stealth include shaping vessels to minimize radar cross-section, using radar-absorbent materials, and employing tactics to reduce electromagnetic emissions and visibility. The document also notes some limitations and countermeasures to stealth technologies.

1. 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

2. 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

3. 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)

4. 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.

5. 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

6. 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

7. 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.

8. 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.

9. 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.

10. 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

11. 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.

12. 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.

13. 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.

14. 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.

15. 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.

16. 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

17. 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

18. 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.

19. 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.