1. BIHE University
Department of Civil Engineering
Airport Engineering– CIV4117-S12
Aug-2012
Overview
Stealth Technology
Course: Airport Engineering
Course ID: CIV4117-S12
Instructor: Mr. Houtan Pourkhorsand
Date: Friday, August 24, 2012
Presenter: Naeem Rezghi
Spring 2012

2. Outline
• Introduction
• History
• Types of Detection
• Radar Cross Section (RCS)
• Reduction in RCS
• Methods of Stealth
• Pros and Cons
• Conclusion

3. Introduction
• What’s stealth technology?
– A technique of making objects invisible
– An important technology used in military operations.
– Also known as LOT (Low Observable Technology)

4. Introduction [Cont’d]
• Most famous stealth aircrafts around the world

5. Introduction [Cont’d]
• Task of Stealth Technology
– Partially invisible objects to radar
– Aircrafts cannot be fully invisible
– An example of this technology in other military field:
A camouflaged soldier

6. History
• World War II played in important role in stealth
technology development.
• Germans were the 1st developers
• Germans developed the stealth Nano-paint
during the WWII! (In recent years the MIT scientists
became successful of making such a similar thing)
Figure 4 – Hitler’s first stealth aircraft
Figure 4 – Hitler’s first stealth aircraft

7. Types of Detection
• Different radar signatures of vehicles can be
categorized as following:
– Radar Cross Section (RCS)
– Infrared signature
– Acoustic signature
– Visible signature
– Laser Cross Section
– Magnetic signature

8. Radar Cross Section (RCS)
Figure 5 – RCS of an aircraft

9. Radar Cross Section (RCS)
[Cont’d]
• A sample of RCS evaluating:
– B-26 aircraft
– 3 GHz frequency signal
– Signal direction is variable
Figure 6 - RCS graph for B-26

10. Radar Cross Section (RCS)
[Cont’d]

11. Radar Cross Section (RCS)
[Cont’d]
• The RCS value for different types of obstacles
are categorized in the following tables:

12. Reduction in RCS

13. Reduction in RCS [Cont’d]

14. Methods of Stealth
• Vehicle shape
• Coating and Absorbers
– Composite materials
– Stealth Nano-carbon paint
• Infrared stealth
– Black Hole Ocarina (BHO) system
– Film Cooled Tailpipe (FCT) system
• Visual stealth
• Plasma stealth

15. Methods of Stealth [Cont’d]
• Vehicle shape
– It should be coated with the Radar Absorbing
Materials.
Figure 9 – Radar absorbing materials

16. Methods of Stealth [Cont’d]
• Vehicle shape
– It should be coated with the Radar Absorbing
Materials.
– It’s tail should kept an ACUTE angle.
– Planes wings has to kept at Angle.
– Design of Nose.
Figure 10 – F117-A geometric design

17. Methods of Stealth [Cont’d]
• Vehicle shape
– It should be coated with the Radar Absorbing
Materials.
– It’s tail should kept an ACUTE angle.
– Planes wings has to kept at Angle.
– Design of Nose.
– Stealth aircraft must embed the Engines within the
wing or fuselage.

18. Figure 11 – B-2 bomber design details

19. Methods of Stealth [Cont’d]
• Coating and Absorbers
– Generally four types of composite materials are
existed:
– PMCs [Polymer Matrix Composite materials]
Figure 12 – PMC materials

20. Methods of Stealth [Cont’d]
• Coating and Absorbers
– Generally four types of composite materials are
existed:
– PMCs [Polymer Matrix Composite materials]
– MMCs [Metal Matrix Composite materials]
Figure 13 – MMC materials

21. Methods of Stealth [Cont’d]
• Coating and Absorbers
– Generally four types of composite materials are
existed:
– PMCs [Polymer Matrix Composite materials]
– MMCs [Metal Matrix Composite materials]
– CMCs [Ceramic Metal Composite materials]
Figure 14 – CMC materials

22. Methods of Stealth [Cont’d]
• Coating and Absorbers
– Generally four types of composite materials are
existed:
– PMCs [Polymer Matrix Composite materials]
– MMCs [Metal Matrix Composite materials]
– CMCs [Ceramic Metal Composite materials]
– Carbon Composites
Figure 15 – Carbon Composite

23. Methods of Stealth [Cont’d]
• Coating and Absorbers
– Stealth Nano-carbon paint
– “BLACKEST” know material of the world
– Absorb 99% of the received signal
– Excellent electrical conductivity and high Strength
Figure 16 – Stealth Nano-carbon paint

24. Methods of Stealth [Cont’d]
• Coating and Absorbers
– Visual stealth
– Having a harmony with environment
– Cannot be visually detected

25. Methods of Stealth [Cont’d]
• Coating and Absorbers
– Visual stealth
– New developments:
– Electro-magnetically conductive polyaniline-based
radar absorbent material.
– It is connected into an internal computer of aircraft.
– The system will analyze the whole environment and
compute the best pattern for each side of aircraft.
Figure 18 – Scheme of invisible aircraft

26. Methods of Stealth [Cont’d]

27. Methods of Stealth [Cont’d]
• Coating and Absorbers
– Plasma Stealth:
– Application in stealth technology:
– Plasma will cover the whole body of aircraft
– Plasma cloud will absorb the radar waves and
prevent aircraft’s detection.

28. Methods of Stealth [Cont’d]
• Coating and Absorbers
– Plasma Stealth:
– Application in stealth technology:
– Plasma will cover the whole body of aircraft
– Plasma cloud will absorb the radar waves and
prevent aircraft’s detection.

29. Pros and Cons
• Pros of stealth aircrafts:
– Few number of stealth aircrafts = Huge number of
conventional aircrafts [Economical in long term]
Figure 21 – Stealth aircraft VS. conventional ones

30. Pros and Cons [Cont’d]
• Pros of stealth aircrafts:
– Few number of stealth aircrafts = Huge number of
conventional aircrafts [Economical in long term]
– Keeping enemy in fear of stealth aircrafts’ existence. So
they will remain in defense mood.
Figure 22 – Scheme of confused soldiers by stealth aircrafts

31. Pros and Cons [Cont’d]
• Pros of stealth aircrafts:
– Few number of stealth aircrafts = Huge number of
conventional aircrafts [Economical in long term]
– Keeping enemy in fear of stealth aircrafts’ existence. So
they will remain in defense mood.
– The natural competition of war will result in economically
weakening of the enemy.
– Diplomatic result: Stealth aircrafts have high military
technology and military secrets.

32. Pros and Cons [Cont’d]
• Cons of stealth aircrafts:
– Low speed and maneuverability

33. Pros and Cons [Cont’d]
• Cons of stealth aircrafts:
– Low speed and maneuverability
– Low amount of carried payload
Figure 23 – B-2 sprint and F-117A while falling bombs

34. Pros and Cons [Cont’d]
• Cons of stealth aircrafts:
– Low speed and maneuverability
– Low amount of carried payload
– High RCS while using of weapons
Figure 23 – B-2 sprint and F-117A while falling bombs

35. Pros and Cons [Cont’d]
• Cons of stealth aircrafts:
– Low speed and maneuverability
– Low amount of carried payload
– High cost:
– B-2 bomber: $2 billion
– F-117A: $70 million
– F-22: $100 million
(x kg) (x kg)
Figure 24 – Scheme of cost analysis of stealth aircrafts

36. Pros and Cons [Cont’d]

37. Conclusion
– Stealth technology is the future of military combat
technology.
– In near future stealth technology can be used in other
facilities like ships, helicopters, vehicles, etc.
– The main problem of this technology is its high cost.
– The pros of stealth technology is in most of cases weighted
to its cons.
– Stealth technology, due to its high cost, cannot be a proper
choice for developing countries such as Iran.
– New developments in other fields of technology such as
Nanotechnology can be used instead of stealth
technology due to their low cost.

38. Any Question?

39. Questions to be answered: