Stealth aircraft

The invention:



The first generation of “radar-invisible” aircraft,
stealth planes were designed to elude enemy radar systems.



The people behind the invention:
Lockhead Corporation, an American research and development firm
Northrop Corporation, an American aerospace firm









Radar



During World War II, two weapons were developed that radically

altered the thinking of the U.S. military-industrial establishment

and the composition of U.S. military forces. These weapons

were the atomic bombs that were dropped on the Japanese cities of

Hiroshima and Nagasaki by U.S. forces and “radio detection and

ranging,” or radar. Radar saved the English during the Battle of Britain,

and it was radar that made it necessary to rethink aircraft design.

With radar, attacking aircraft can be detected hundreds of

miles from their intended targets, which makes it possible for those

aircraft to be intercepted before they can attack. During World

War II, radar, using microwaves, was able to relay the number, distance,

direction, and speed of German aircraft to British fighter interceptors.

This development allowed the fighter pilots of the Royal

Air Force, “the few” who were so highly praised byWinston Churchill,

to shoot down four times as many planes as they lost.

Because of the development of radar, American airplane design

strategy has been to reduce the planes’ cross sections, reduce or

eliminate the use of metal by replacing it with composite materials,

and eliminate the angles that are found on most aircraft control surfaces.

These actions help make aircraft less visible—and in some

cases, almost invisible—to radar. The Lockheed F-117A Nightrider

and the Northrop B-2 Stealth Bomber are the results of these efforts.





 Airborne “Ninjas”



Hidden inside Lockheed Corporation is a research and development

organization that is unique in the corporate world.

This facility has provided the Air Force with the Sidewinder heatseeking

missile; the SR-71, a titanium-skinned aircraft that can fly

at four times the speed of sound; and, most recently, the F-117A

Nightrider. The Nightrider eluded Iraqi radar so effectively during

the 1991 Persian Gulf War that the Iraqis nicknamed it Shaba,

which is an Arabic word that means ghost. In an unusual move

for military projects, the Nightrider was delivered to the Air

Force in 1982, before the plane had been perfected. This was done

so that Air Force pilots could test fly the plane and provide input

that could be used to improve the aircraft before it went into full

production.

The Northrop B-2 Stealth Bomber was the result of a design philosophy

that was completely different from that of the F-117A

Nightrider. The F-117A, for example, has a very angular appearance,

but the angles are all greater than 180 degrees. This configuration

spreads out radar waves rather than allowing them to be concentrated

and sent back to their point of origin. The B-2, however,

stays away from angles entirely, opting for a smooth surface that

also acts to spread out the radar energy. (The B-2 so closely resembles

the YB-49 FlyingWing, which was developed in the late 1940’s,

that it even has the same wingspan.) The surface of the aircraft is

covered with radar-absorbing material and carries its engines and

weapons inside to reduce the radar cross section. There are no vertical

control surfaces, which has the disadvantage of making the aircraft

unstable, so the stabilizing system uses computers to make

small adjustments in the control elements on the trailing edges of

the wings, thus increasing the craft’s stability.

The F-117A Nightrider and the B-2 Stealth Bomber are the “ninjas”

of military aviation. Capable of striking powerfully, rapidly,

and invisibly, these aircraft added a dimension to the U.S. Air Force

that did not exist previously. Before the advent of these aircraft, missions

that required radar-avoidance tactics had to be flown below

the horizon of ground-based radar, which is 30.5 meters above the

ground. Such low-altitude flight is dangerous because of both the

increased difficulty of maneuvering and vulnerability to ground

fire. Additionally, such flying does not conceal the aircraft from the

airborne radar carried by such craft as the American E-3A AWACS

and the former Soviet Mainstay. In a major conflict, the only aircraft

that could effectively penetrate enemy airspace would be the Nightrider

and the B-2.

The purpose of the B-2 was to carry nuclear weapons into hostile

airspace undetected.With the demise of the Soviet Union, mainland

China seemed the only remaining major nuclear threat. For this reason,

many defense experts believed that there was no longer a need

for two radar-invisible planes, and cuts in U.S. military expenditures

threatened the B-2 program during the early 1990’s.



Consequences



The development of the Nightrider and the B-2 meant that the

former Soviet Union would have had to spend at least $60 billion to

upgrade its air defense forces to meet the challenge offered by these

aircraft. This fact, combined with the evolution of the Strategic Defense

Initiative, commonly called “Star Wars,” led to the United

States’ victory in the arms race. Additionally, stealth technology has

found its way onto the conventional battlefield.

As was shown in 1991 during the Desert Storm campaign in Iraq,

targets that have strategic importance are often surrounded by a

network of anti-air missiles and gun emplacements. During the

Desert Storm air war, the F-117A was the only Allied aircraft to be

assigned to targets in Baghdad. Nightriders destroyed more than 47

percent of the strategic areas that were targeted, and every pilot and

plane returned to base unscathed.

Since the world appears to be moving away from superpower

conflicts and toward smaller regional conflicts, stealth aircraft may

come to be used more for surveillance than for air attacks. This is

particularly true because the SR-71, which previously played the

primary role in surveillance, has been retired from service.



See also : Airplane; Cruise missile; Hydrogen bomb; Radar;
Rocket; Stealth aircraft Wikipedia .