STEALTHSTEALTH TECHNOLOGYTECHNOLOGY

Presented byPresented by

Akhilesh Akhilesh

09H51A030209H51A0302

What is it?What is it? Stealth is defined as being secretive or Stealth is defined as being secretive or

cautious in movement and action.cautious in movement and action. RADAR is used to detect position of objects. RADAR is used to detect position of objects. Technology avoiding detection and Technology avoiding detection and

innovating deception is known as stealth innovating deception is known as stealth technology.technology.

RCS (Radar cross section)reductions, RCS (Radar cross section)reductions, acoustics, thermal and other EM emissionsacoustics, thermal and other EM emissions

How is it achieved.How is it achieved. Absorbs radar waves or deflects to other Absorbs radar waves or deflects to other

directions.directions. Minimizes heat and other emissions from Minimizes heat and other emissions from

engine and other spots.engine and other spots. Makes difficult to detect except closely.Makes difficult to detect except closely. The size of a target's image on radar is The size of a target's image on radar is

measured by RCS (σ )measured by RCS (σ )

Smooth edges receive maximum radio wave Smooth edges receive maximum radio wave reflectors.reflectors.

A stealth aircraft on the other hand, is made up of flat A stealth aircraft on the other hand, is made up of flat surfaces. When signal hits a stealth plane the signal surfaces. When signal hits a stealth plane the signal deflects away like thisdeflects away like this..

Vehicle shape and structure

Mainly plain form alignment. Mainly plain form alignment. The leading edges of wing and tail The leading edges of wing and tail

surfaces set at same anglessurfaces set at same angles..

Vehicle structure (contd..)

Use of re-entrant triangles behind Use of re-entrant triangles behind skin.skin.

Distinctive serrations used in Distinctive serrations used in external airframes.external airframes.

Propulsion subsystem shaping.Propulsion subsystem shaping.

Now in research is fluidic nozzles Now in research is fluidic nozzles for thrust vectoring.for thrust vectoring.

Vehicle structure (contd..)

Radar Absorbing Materials (RAM)Radar Absorbing Materials (RAM) RAMs often as paints used to absorb RAMs often as paints used to absorb

RADAR signals.RADAR signals.

Iron ball paint, ferrite in polymer Iron ball paint, ferrite in polymer matrix used.matrix used.

The cockpit canopy coated with thin The cockpit canopy coated with thin layer of indium tin oxide .layer of indium tin oxide .

Small cell foams painted or loaded with absorbing Small cell foams painted or loaded with absorbing ink.ink.

MAGRAMMAGRAM

R- CardR- Card

Absorbing honeycombAbsorbing honeycomb

Transparent RAMTransparent RAM

RAMs (contd..)

Major IR emission sources.Major IR emission sources.

1. Tailpipe region1. Tailpipe region

2. Turbojets have exhaust gas temperature of 2. Turbojets have exhaust gas temperature of 10001000ooCC

3. Exhaust gas plume3. Exhaust gas plume

4. Hot engine parts4. Hot engine parts

5. Aircraft skin (frictional heating) 5. Aircraft skin (frictional heating)

6. Reflected and reemitted sunlight6. Reflected and reemitted sunlight..

IR Emission

IR ReductionIR Reduction

Using surface paintsUsing surface paints

Non circular tail pipeNon circular tail pipe

Emissions from hot parts screened by Emissions from hot parts screened by airframe.airframe.

The plume mixed with cool air.The plume mixed with cool air.

Electromagnetic emissionsElectromagnetic emissions

The greatest source is RADAR itself.The greatest source is RADAR itself.

Shutting down RADAR a solution Shutting down RADAR a solution having negative effects.having negative effects.

Radio /radar altimeters and Doppler Radio /radar altimeters and Doppler navigationnavigation systems.systems.

Conclusion.Conclusion. Stealth technology developed a lot.Stealth technology developed a lot.

Investment needed is very high.Investment needed is very high.

High chance of low cost gain.High chance of low cost gain.

A lot learned about signature reduction A lot learned about signature reduction and absorption.and absorption.

Useful for other projects.Useful for other projects.

Success yet to be proved extensively.Success yet to be proved extensively.

ExamplesExamples F 117 F 117

B-2 BomberB-2 Bomber

F-22 Raptor( From YF 23 Platform)F-22 Raptor( From YF 23 Platform)

SR-71 Black birdSR-71 Black bird

HMS Helsingborg HMS Helsingborg