Saturday, February 12, 2011

How does a Stealth Aircraft Work?

" Stealth " has been probably the most repeated word in military aviation for the past few years. Now comes the basic question that many have - what is it and how does such an aircraft work?

Stealth is just the ability of an object to prevent itself from being detected by a radar. A radar basically sends out radio waves into the sky ,which then bounces off the bodies of aircraft and returns , to be detected by the radar computer.
          Now, the amount of radar rays "reflected" by an aircraft is called its "Radar Signature ", which is used to calculate its size,speed and the location.

To be undetected, an aircraft must fly either too high ( which makes it impossible to hit targets on ground accurately) , or too low to be detected by a radar ( no need of radars, it becomes visible to naked eye :-) ).
This leaves with only one option- to fly normally and stop reflecting radio waves.
Easier said than done isn`t it? But yes, there are ways :-

1) Using a RAM ( No, not your computer RAM) which is, the Radar Absorbent Material. This is a coating on the airplane surface which precisely does the same thing- absorb radio waves,and scatter `em in all directions undetectable by the radar. Eg. wood powder and other chemical compounds, which are kept top secret, for obvious reasons.

2)Having a sleek, smooth aerodynamic design. This reduces the "cross section area"of the plane.lesser the area, lesser the radio wave reflection. Common sense , isn't it? Have a look at the pictures below:

A Stealth Aircraft

A traditional large Aircraft
Due to these, the Radar Signature for stealth planes is very very less... almost like that of a bird ( for the B-2 Stealth bomber shown above) compared to the traditional plane ( the B-52 bomber) whose signature is about that of a huge trailer truck !
        Now you may get an idea of how difficult it would be to deal with stealth fighters/bombers in an actual battle scenario.. no wonder countries around the world are scrambling to get hold of these beauties- The B2 Spirit,F-22 Raptor,F-35 Lightening II , and many more under development in labs around the world.No Radar could possibly see it, and the hideous birds can play havoc in enemy territory. Boom !Boom!Boom!
It would be pretty much like finding a needle in a haystack.
     So..... A stealth plane could be a road to total aerial dominance right?Not quite.. Technology always evolves, and it does so in this case too.
As they say, every great warrior has his Achilles`s heel :-)
More on that in my next post.


Anonymous said...

Stealth aircraft r designed such they reflect radiowaves, this s done by using RAM also by adding sharp edges to the crafe, so to bounce the waves, check out B2/F114/F22. They all have sharp angels, Also the craft s designed in such a way that its heat signature s very minimal...... Nishant

Arvind T.M. said...

the aircraft propulsion system is so designed that the infrared sensors don`t detect it.
As far as total stealth is concerned, its not possible. when these planes are dropping ammunition they open up their cargo bay doors , which does`nt have stealth capability.This is one major vulnerability- even with the F-35.

And btw, its F-117 Nighthawk

Anonymous said...

yup, it s F-117. I forgot it... to many air crafts nos, i mmix em up..... I heard Russia n HAL s developing our own stealth aircraft due by 2018...

Arvind T.M. said...

yes,, its called the PAK-FGFA.will give the F-22 a real run for money.
THis is the precise reason y India turned down the US offer to buy F-35s. It din want to have 2 types of 5th gen fighters in a single force.

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