Air Force officials in Honolulu yesterday said the first crash of a B-2 stealth bomber was caused by moisture in sensors and estimated the loss of the aircraft at $1.4 billion.

The crash probably could have been avoided if knowledge of a technique to evaporate the moisture had been disseminated throughout the B-2 program, said Maj. Gen. Floyd L. Carpenter, who headed an accident investigation board.

The "Spirit of Kansas" abruptly pitched up, rolled and yawed to the left Feb. 23 before plunging to the ground at Andersen Air Force Base on Guam. Both pilots ejected safely just after the left wing made contact with the ground in the first crash since the maiden B-2 flights nearly two decades ago.

"It was just by the grace of God that they were safe, and the good (ejection) system," Carpenter said at Hickam Air Force Base.

Water distorted preflight readings in three of the plane's 24 sensors, making the aircraft's control computer force the B-2 to pitch up on takeoff, resulting in a stall and subsequent crash.

Carpenter said the pilots and crew followed procedures and "the aircraft actually performed as it was designed. In other words, all the systems were functioning normally."

However, a technique learned by some two years ago that had gone widely unknown and unadopted probably would have prevented the crash, Carpenter said.

The technique essentially heats the sensors and evaporates any moisture before data calibrations.

"This technique was never formalized in a technical order change or captured in 'lessons learned' reports. Hence, only some pilots and some maintenance technicians knew of the suggestion," according to Carpenter's executive summary of the accident.

"The human factor of communicating critical information was a contributing factor to this mishap," the report said.

The sensors measure air pressure to help calculate everything from air speed to altitude. Because of the bad data, flight computers had inaccurate air speed and wrongly indicated a downward angle, which contributed to an early rotation and uncontrolled 30-degree pitch up.

Carpenter said the lack of altitude and air speed prevented the pilots from correcting the aircraft.

The bomber had been returning to Whiteman Air Force Base in Missouri, where the 21-plane fleet is based. The Air Force grounded the B-2s and resumed flying them in late April.

Carpenter said procedures and policies are now in place to guard against similar crashes.

Guam, 3,700 miles southwest of Hawai'i, is known for its humidity. But the Air Force said water in the sensors never caused any problems.

"We never saw this very often. Even when we did, the data calibration typically fixed the problem," Carpenter said in a conference call.

"So it never became an issue that the maintenance supervisors became aware of because the jets continued to fly perfectly fine."

The general said his responsibility was solely for the investigation of the crash and added that the report was forwarded to commanding officers to determine if any disciplinary actions are required.

"It's fortunate the crew was able to safely eject. It's unfortunate, however, that we lost one of our nation's penetrating bombers," said Gen. Carrol H. Chandler, commander of Pacific Air Forces.

Chandler said the B-2s with other Air Force bombers "maintain a continuous presence in the Pacific, underscoring our commitment to stability and security in the region."

"I believe that forward presence and the need for bombers in the Pacific is unlikely to change in the near future," he said.