Trials of the F-l 11

The F-111 is probably the most controversial plane ever built. Ever since former Defense Secretary Robert McNamara overruled the top military leaders in 1962 and gave the contract for the 1,650-m.p.h., two-seat fighter-bomber to General Dynamics, the plane has had to fly through a barrage of verbal flak. It has been the center of several congressional investigations, been frequently attacked in the press as deficient in performance and criticized relentlessly by the U.S. Navy, which complains that its version is hopelessly overweight for carriers.

Last week, as the first six of the new planes made their combat debut over North Viet Nam, the F-l 11 flew right into another, even more serious controversy. On only the third and sixth days of combat, two of the $6,000,000 planes went down in Southeast Asia. One of them failed to return to its base in Thailand on a bombing mission to North Viet Nam; the other crashed in Thailand.

Escape Module. The North Vietnamese quickly claimed that their gunners had downed the first F-l 11 lost, but there were some indications that it may have crashed somewhere on the way to its target over the southern, or panhandle, part of North Viet Nam. U.S. pilots speculated that the F-l 11, which sweeps in at treetop level on bombing runs, may have run into a hill or mountain. Not surprisingly, the Air Force slapped on a tight security blackout. Since the plane is crammed with the very latest navigational and other electronic gear, the U.S. did not want to let the enemy know whether it fell over the North or in Communist-held portions of Laos. The Pentagon confirmed that the second F-l 11 crashed in Thailand after what the Air Force described as "an in-flight" emergency; both of its crew members parachuted to safety in the F-lll's detachable escape module.

The F-l 11 's ill-starred debut cast doubts on what is, on paper, an impressive fighting machine. The plane can fly faster and farther than any earlier U.S. fighter-bomber and lift twice the bomb load (12,500 Ibs.). Its great strategic importance in Viet Nam was to be that its new inertial guidance and radar targeting system enables it to bomb in foul weather or fair, either by night or by day. Its arrival in force would thus mean that the U.S. could keep up its aerial bombardment of the North despite monsoon rains or heavy cloud cover.

Under the Net. The F-111 is the world's first combat plane with the so-called "variable geometry" wing, which extends for greater lift during takeoff and landing, folds back for less drag at supersonic speeds. Its "terrain radar," which automatically adjusts the plane's altitude to accord with the topography, is supposed to enable the plane to hug the ground while flying at a speed of 900 m.p.h. and thus dash in below the enemy radar net. If the first F-111 did hit a mountain, it was probably due to a malfunction in the terrain radar. The Russians, who have been experimenting with a swing-wing plane of their own, would learn a great deal if they could retrieve parts of the F-111.

The other four F-111s carried out a dozen or so successful raids against supply and troop staging areas in North Viet Nam's panhandle. The Air Force has ordered 395 of the swing-wings, but the Navy still does not want the plane. As the Senate Armed Services Committee last week voted to cancel funds for any further development of the naval version, Senator John McClellan, the F-111's leading critic, called the Navy's swing-wing "a dog" in a Senate speech. In the middle of his speech, an aide handed him the bulletin that the first Air Force F-111 was missing in action.

This file is automatically generated by a robot program, so reader's discretion is required.