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Stealth aircraft


ABSTRACT

Stealth aircraft are aircraft that use stealth technology to make it
harder to be detected by radar and other means than conventional
aircraft by employing a combination of features to reduce
visibility in the visual, audio, infrared and radio frequency (RF)
spectrum. Well known examples include the United States' F-117
Nighthawk (1980s-2008), the B-2 Spirit "Stealth Bomber," and
the F-22 Raptor.
While no aircraft is totally invisible to radar, stealth aircraft limit
current conventional radar's abilities to detect or track them
effectively enough to prevent an attack. Stealth is accomplished
by using a complex design philosophy to reduce the ability of an
opponent's sensors to detect, track and attack an aircraft.
Modern stealth aircraft first became possible when a
mathematician working for Lockheed Aircraft during the 1970s
adopted a mathematical model developed by Petr Ufimtsev, a
Russian scientist, to develop a computer program called Echo 1.
Echo made it possible to predict the radar signature an aircraft
made with flat panels, called facets. In 1975, engineers at
Lockheed Skunk Works found that an airplane 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.
Reduced radar cross section is only one of five factors that
designers addressed to create a truly stealthy design. Designers
also addressed making the aircraft less visible to the naked eye,
controlling radio transmissions, and noise abatement.