War In The Balkans: Terrain Offers Clue To Why Jet Came Down

So did it "malfunction" or was it shot down? The question of what caused a F-117A Nighthawk "Stealth" fighter to fall from the sky over Serbia on Saturday night has still to be conclusively answered.

Despite the fact that the pilot, who should know a few things about what happened, was rescued within hours, Pentagon officials say they are still conducting their investi- gation.

Certainly it is important to get the answer right. If it was because of a broken part, pilot error or a lucky shot from anti-aircraft gunners, then there is not too much of a problem. But if it meant that the stealth technology didn't work, then a lot of people are going to go back to a lot of drawing boards.

"It felt like a knife through the stomach," was the reaction of one engineer from the aircraft's design programme when he heard the news. The US has spent a total of $50bn on developing this aircraft, the B-2 bomber and a new generation of fighters.

Other experts said that it was a surprise that the secret had lasted so long, given that the F-117A technology was developed in the Seventies.

During the Gulf war the aircraft flew more than 1,200 sorties without a single plane being damaged by Iraqi fire, a feat that even amazed air force chiefs. But that was over a flat desert terrain, similar to that of the Nevada desert where it was designed.

Some experts feel it could be the terrain of Yugoslavia that has made the difference. Flying over this mountainous landscape, where targets are easily concealed, it is likely the planes would have to carry out manoeuvres which could seriously affect its "stealth" characteristics.

Even a standard banking turn increases the aircraft's radar profile by 100 times, sources say.

John Davison