Seeing Through Stealth

For the Serbs, it was a trophy of war. Late last March CNN cameras showed Serbian women dancing on the wing of an American warplane smoldering on the ground near Belgrade. After the initial shock, most Americans soon shrugged off the incident. The pilot was quickly rescued, and during the rest of the 78-day air war, Serb gunners brought down only one other American plane, whose pilot also returned safely. But the image of that broken black wing still haunts the Pentagon.

The wing belonged to an F-117 stealth bomber. Stealth aircraft were advertised as virtually invisible, extremely difficult to detect by radar. Yet this F-117 Nighthawk had been picked up and "painted" by a jury-rigged Soviet-made radar and knocked out of the night sky. Was it a lucky shot? Or are stealth warplanes not so stealthy after all?

That is a trillion-dollar question for the Pentagon. In addition to the 64 F-117s (cost: $90 million per plane) and the 21 B-2 bombers (cost: $2.5 billion per), the military has ordered up $70 billion worth of next-generation F-22 Raptors to replace its workhorse fighters, the F-16s and F-15s. In 1994 the then Defense Secretary William Perry promised that the Raptor would be "essentially invisible." The Army is getting into the act with a stealth helicopter, the $28 million-plus Comanche ("Invisible. Inaudible. Incredible," according to its maker, Boeing Sikorsky). Even the Navy, which blew $5 billion trying and failing to build a stealth attack plane, the A-12 Avenger, is incorporating stealth designs into its warships.

The Air Force has been quietly trying to reconstruct the last mission of the F-117 brought down on March 27. The details are classified, but NEWSWEEK has been able to piece together the essential outline from Pentagon sources and industry experts. The bottom line appears to be that stealth technology has been oversold and that stealth warplanes are vulnerable to a variety of countermeasures that are within the grasp of America's enemies.

Stealth technology is unforgiving of the smallest mistake. Stealth planes are designed with sharp angles or compound curves to deflect radar, and special composite materials that are supposed to reduce the planes' radar "signature." But it can never be eliminated, so before every mission, ground crews spend hours working to "tape and butter" the F-117--making sure the seams are even and smoothing over any rough spot that might reflect back a radar beam. (The skin of the plane is highly toxic--those Serbian women who danced on the still-smoking wing last March run a high risk of developing malignant cancers.) Before a stealth mission, the bombing run has to be carefully charted. The locations of all known enemy radar sites are fed into a computer dubbed "El-vira, Mistress of the Night." The computer maps a course to take advantage of blind spots in the enemy's radar coverage. But to plot a safe course, Elvira must know the locations of enemy radars, which can be hidden.

The Serbs were apparently able to outfox Elvira. For three nights preceding the flight of the doomed F-117, stealth warplanes had flown essentially the same track on bombing runs. The Serbs moved their radars each day and turned them on only briefly--just long enough to get a snapshot of the course of the incoming warplanes, but not long enough to be spotted by NATO's radar-detecting aircraft. On the fourth night, the Serbs were waiting with radars updated by the Russians to help defeat the stealth bomber. As the American warplane dropped its bombs on a target near Belgrade, the F-117's open bomb-bay doors made the jet "look like a barn on radar," according to a senior Air Force official. The Serbs quickly fired off missiles. Suddenly under attack, the F-117 pilot dropped below the clouds.

A bad idea, say stealth pilots. F-117s are painted black. Some of its designers argued that a milky blue color would provide better camouflage, but the Air Force "didn't think that was manly enough and ordered them painted black," said a senior government official who helped write a classified study of the 1991 Persian Gulf air war. On a moonlit night, silhouetted against the clouds like the "Batman signal," the plane made a fat target. The Serbs opened up with antiaircraft guns, and a 57-mm shell tore a hole in one wing. (For the record, the Air Force will say only that the plane was brought down by a "combination" of factors.) The pilot was lucky to escape: the G-forces were so great that he reached the ejection-seat handle only with difficulty. American search-and-rescue teams found the downed pilot hiding in a culvert after six hours. The Serbian search parties' dogs had come within 30 feet of his hideout.

The Air Force has kept the pilot under wraps, so it is difficult to know to what degree pilot error may have contributed to the downing of the F-117. But stealth experts interviewed by NEWSWEEK say that the plane is inherently vulnerable. Another F-117 was shot up on a bombing mission, sources say, and limped back to base. The Serbs' Russian-made low-frequency radar is capable of picking up stealth planes, probably not head-on, but from the side and the rear. Stealth warplanes are more vulnerable to newer technology. Doppler radar can zero in on the wake of a stealth plane, and infrared radar can pick up its heat emissions. An infrared radar on a Navy F-14D fighter flying near the China Lake testing grounds in California suddenly lit up not long ago; the pilot had inadvertently locked on to a B-2 bomber.

Some Air Force officials blame the media for exaggerating the prowess of the F-117, which performed well in the gulf war. But eager for money from Congress, the military has played into the hype, handing out charts showing how just a few stealth planes can do the job of a much larger fleet of conventional aircraft. The charts are misleading. They do not acknowledge that the stealth aircraft must still be accompanied by planes designed to jam enemy radars. And already, informed sources say, cost overruns on the F-22 Raptor are approaching $1 billion. Last week the Pentagon produced a two-star Air Force general who, speaking to NEWSWEEK on background, denied this and downplayed stealth technology's problems. But Chuck Myers, a former combat pilot and an early pioneer of stealth design, bluntly told NEWSWEEK that the F-117 and B-2 are "not stealthy at all. They have to fly at night; they can't fly during the day. We never produced a stealthy airplane."