Winged Wonder

Unveiling a newborn fighter

At Grumman Aerospace Corp.'s test-flight complex on Long Island, a band struck up The Stars and Stripes Forever. Then, as 1,500 employees and dignitaries applauded, the curtain rose on the X-29A, the experimental plane that the Air Force hopes will spawn a new generation of fighters. "That's a beautiful model," said Vice President George Bush, on hand to honor the new plane, "but they've got the wings on backward."

No, the wings are on right; they are supposed to sweep forward. They are mounted at the tail end and pitched ahead at a 35DEG angle. The configuration increases lift, reduces drag, prevents stall outs, and allows the X-29A to turn on a dime at supersonic speeds. Just behind the cockpit are gill-like projections called canards, the French word for ducks. Indeed, the plane resembles a mallard in full flight.

During World War II, the Germans built an experimental Junkers JU-287 jet bomber with wings that raked sharply forward. The plane flew well in tests. But once the sound barrier was broken in 1947, the design presented a problem: forward-swept wings tore away from the fuselage at supersonic speeds, and strengthening the wings with steel or aluminum made the craft unacceptably heavy. Now, newly developed graphite-epoxy composites can produce a wing stronger than steel and up to 45% lighter. These materials form the skin of the X-29A's wings.

But the unique design makes the X-29A as skittish as a colt. "It's roughly like throwing an arrow backward," says Robert Roemer, head of the X-29A project for Grumman. "No human could handle the multitude of adjustments necessary to keep this bird in stable flight." So three computers do the work for the pilot, making 40 adjustments a second to the wings and canards to keep the plane from ripping apart. In effect, the pilot guides he plane by feeding directions into the computer. If all the computers were to fail, the X-29A would self destruct in a mere two-tenths of a second.

Bush's appearance last week at the X-29A's roll-out underscores the Pentagon's interest in high-tech fighters and the Administration's desire to publicize its military buildup in an election year. If successful, the plane, which will serve as a laboratory for new systems, will become a blueprint for fighter jets of the future. Says Robert Cooper, director of the Pentagon's Defense Advanced Research Projects Agency: "We decided we had to return to the days when we were willing to take major risks to make spectacular advances."