The Air Force is bringing the B-2 stealth bomber, the crown jewel of its supersecret "black inventory," out from behind the veil of secrecy that has shrouded it for a decade.

The high-technology flying-wing aircraft, designed to penetrate enemy radar defense and drop nuclear bombs, was being unveiled Tuesday by Northrop Corp. at a rollout ceremony - although at a secure distance of 200 feet."It is simply not comparable to anything ever done before. It is the first real computer-age aircraft," Northrop spokesman Les Daly said Monday in one of the aerospace company's first public pronouncements about the B-2.

Daly referred to an aircraft that has not yet flown and which the General Accounting Office estimates could cost taxpayers up to $68.5 billion if the Pentagon builds the 132 aircraft-fleet sought by the Air Force.

The B-1B, the Air Force's most current operational nuclear bomber, came in around $250 million apiece, before modifications. Stealth bombers could cost twice that.

In remarks prepared for delivery at the rollout, Air Force Secretary Edward C. "Pete" Aldridge Jr. said, "Let all of us remember America's enduring hope and prayer that the B-2 will strengthen the cause of peace and that this magnificent aircraft will never be flown in anger."

Critics have questioned the need for such a plane and called it a destabilizing element in arms-control efforts. Gen. Larry D. Welch, Air Force chief of staff, contends the B-2 will play a vital role in America's defense.

The stealth, so-called because it is intended to be extremely difficult to detect on enemy radar, has been described as a dark, tail-less flying wing with no sharp angles to reflect radar and built of exotic composite materials, some of which will absorb radar rather than reflect it.