Introduction


Stealth. The word summons images of fighter jets and bomber sneaking over
enemy lines, jinking around objects while hugging the Earth to avoid detection of
batteries of radars eagle eyed sentinals.

What this project deals with is how aircraft are detected by radar, what Stealth
Technology is, the development of this technology, and the advantages of and
disadvantages of Stealth.


What is Stealth Technology ?


Stealth Technology is the technology in which a plane or other vehicle is made to
be virtually undetectable to radars and radar signals.


How Radar Signals Are Blocked
Using Stealth Technology


Radar signals that are sent towards an aircraft that has stealth features can cause
radar signals that are sent out by a radar unit by having the signals hit a part or all of the
aircraft and what happens to those signals is that they either pass right through the
aircraft or they are reflected towards another direction and this is caused because of the
Radar Absorbent Material (RAM) and in this way the aircraft can be virtually
undetectable to radar.


The Development of Stealth Technology


This Technology was cloaked in a veil of secrecy for almost two decades, but
this entirely new family of aircraft has recently been announced to the public but the
United States Department of Defence. These aircraft are virtually undetectable to radar,
these new aircraft are the first examples of '' law observable, or stealth technology.
Because radar in the primary means by wich aircraft are detected and tracked, it has
become very important to the military service to make aircraft as invisible to radar as
possible. By building aircraft in certain ways or out or out of certain materials like exotic
plastics, it is possible to control the direction or deduce the amount of radar energy they
reflect. This prevents energy radar systems from spotting or tracking '' stealth'' aircraft
and from using weapons like anti-aircraft missiles to destroy them.

There were attempts to build an aircraft that was ''stealthy ''with a low observables
'' pair to the revelation of the new ''stealth'' aircraft family. Among these aircraft was a
special lockhead U-2 reconnaissance aircraft painted with a coat of radar-absorbent
material. Lockhead's famous SR-71 , wich was the first aircraft to build from scratch that
had a reduced radar return were the two highly classified Lockheed "Have Blue"
prototypes. These aircraft were equipped with flat surfaces that reflected radar energy
away from the radar's receiver, this reducing the chances of detection.

An operational descendant of the "Have Blue" aircraft has become well known as
the Lockheed F-117. This fighter- bomber has proved to be very successful in actual
combat. The Northrop B-2 intercontinental range bomber is the latest "stealth" aircraft to
be made public. It is built primarily of plastic-like composite materials, the B-2 avoids
radar detection by absorbing radar energy or by allowing it to pass through with out being
reflected. A "stealthy" fighter, the U.S. Air Forces Lockheed F-22, is also presently under
development and may be in production at the end of this century. "Stealth" is expected to
become an integral part of all U.S. military aircraft designs from now on.








Radar Reduction


Because the advantages of "stealth" technology outweigh the disadvantages, these
are considered nessecary evils, when a "stealth" aircraft is built. Increased empty weights
resulted from the addition of external radar absorbent coating (RAM). From the engines,
that are buried inside the structure of the aircraft. Which are put there to reduce the
amount of heat they generate and from exotic and sophisticated engine exhaust nozzles
that also help reduce heat generation. Finally a full complement of heavy and
space-consuming electronic countermeasures equipment which is a part of the aircraft's
defenses adds to it's weight. All of these add weight that otherwise would not be an
encumbrance, and weight equates to penalties in speed, range, and altitude performance.

Another problem with incorporating "stealth" technology into an aircraft is a
wing shape that does not provide the optimum amount of lift. The resulting increase in
drag reduces flight performance. "Stealth" shapes, such as the faceting found on the
Lockheed's F-117 stealth fighter, also tends to be aerodynamically destabilizing. This is
brought under control only through the use of highly sophisticated computers that serve
to electronically balance the aircraft while it is in flight through it's autopilot and control
system.

Because range is reduced by many of the "stealths" physical constraints, "stealth"
aircraft sometimes need to be bigger than the designers of the craft would like in order to
carry sufficient fuel. "Stealth" aircraft can't be equipped with external fuel tanks because
doing this would