A Lethal Video Game

Hurtling along near the speed of sound in dead of night, at times under intense antiaircraft fire, how could pilots of the F-111 fighter bombers plant so many of their bombs on or near targets as small and discrete as a single building or a row of planes? By high-tech wizardry that makes a real-life bombing run seem almost as simple as a video game.

The prime weapon of last week's raid was an advanced version of the F-111 fitted with a special electronics navigation and targeting pod known as Pave Tack. Developed by Ford Aerospace & Communications and first delivered to the Air Force less than six years ago, the pod fits in the weapons bay of the F- 111 and allows the pilot to find his target in total darkness while moving at very high speed.

As they flew to within 30 miles of the Libyan coast, weapons-systems officers (called whizzos), who sit beside the pilot on each F-111, went into action. They lowered the Pave Tack pods, which began sweeping the horizon first with radar and then with infrared cameras, transmitting fairly detailed pictures of the ground below to a radar-infrared scope that is like a small television screen on the aircraft's instrument panel. The whizzos knew what to look for: before taking off from England, they had thoroughly studied aerial- reconnaissance photographs of their targets. In addition, information to find and identify targets had been fed into the F-111s' computers.

At 90 sec. from target, with the plane at an attack altitude of less than 500 ft. and streaking along at 600 m.p.h., the whizzo sees an infrared image of his quarry on his screen and directs a pencil-thin laser beam toward it. This step, called target designation, or painting, supplies the plane's computer with the exact range to the target.

One minute away, the whizzo tells his pilot that the computer is locked on to the target. The pilot presses a button on his throttle, turning command of the plane's bomb-release mechanism over to the computer. As the plane roars toward its target, the bombs are released to drop in a controlled fall. Then, in what is called a toss, an evasive maneuver to avoid damage by the explosion of his own bombs, the pilot suddenly takes the plane up to about 1,200 ft. Though the plane is wrenching upward, the Pave Tack system, mounted on a device that can swivel 360 degrees , keeps its laser eye on the target all the while.

In last week's mission, the F-111s used 2,000-lb. bombs of the Paveway II ! class. The bomb's nose contains a laser-sensing device, a computer and small movable fins for stabilization and control. The sensor homes in on the reflection of the laser off the target; the computer moves the fins to make minute midcourse corrections. Each F-111 emits a laser at a different frequency, which only its bombs are programmed to detect.

Known as precision-guided gravity bombs, these ungainly guppy-shape munitions were around in a less sophisticated form in the Viet Nam War. The Paveway IIs are actually a technological notch below the Harpoon and HARM missiles used last month in the Gulf of Sidra. Those devices are called smart bombs because they have their own propulsion and guidance systems to direct themselves to a target, enabling a pilot to "fire and forget." Nonetheless, F-111 flyers are still confident about what they can do with the plain old Paveway II. Even though the F-111s did not put a bomb squarely on Gaddafi's tent last week, they did not miss by much.