Software bug may cause Patriot missile errors

U.S. Central Command said that the U.S. military is investigating the possibility that a software problem in the Patriot Missile defense system may be responsible for targeting two friendly aircraft, but that other scenarios could just as likely be responsible for the mishaps.

"They're looking into a software problem. They're going to check everything out. When they do find a fault, they'll put it out to the rest of the world," said Navy Lt. Commander Charles Owens.

On Sunday, a Patriot Missile battery on the Kuwait border accidentally shot down a British Royal Air Force (RAF) Tornado GR-4 aircraft that was returning from a mission over Iraq. Two British pilots were killed in the incident.

Then on Monday a U.S. F-16 fighter jet fired at and destroyed a Patriot battery's radar dish after the pilot said the Patriot had "locked on" to the plane.

Published reports have linked the mishaps to software problems with the Patriot.

A Washington Post story on Tuesday quoted unnamed Pentagon officials saying that the cause of the incidents was "obviously a software glitch."

According to the Post, the crew of the Patriot battery had "taken cover" from incoming artillery shortly before the F-16 was locked on to by the Patriot, leaving the missile battery to operate "largely on automatic."

A story on the Web site of Radio Australia also quotes an unnamed British Royal Air Force commander saying that a software "glitch" led to the accidental downing of the RAF plane.

The software error caused the missile battery to read the RAF Tornado as an Iraqi missile, according to the Radio Australia report.

In a briefing at U.S. Central Command in Doha, Qatar, on Thursday, however, General Vince Brooks, deputy director of operations, said that more needs to be known about the downing of the Tornado before the military makes a statement.

"We had the unfortunate incident with a Patriot Missile against a U.K. GR-4 aircraft. We will be truthful with you about it when we know some more, but right now, all reports are currently under investigation," Brooks said.

In a briefing on Saturday, Major General Peter Wall said that the army checked its procedures for the Patriot following the incident and was "satisfied."

Defense industry experts disagreed about the possibility of a software problem being solely responsible for downing a friendly aircraft.

"An operator has to lock on," said one industry expert who is familiar with the operation of the Patriot.

"If you're sitting in there, the radar is tracking everything in the sky. The operator moves a track ball, puts on one of the symbols, clicks on that and pulls up all the information -- speed, heading, altitude."

That information, as well as an Identification Friend or Foe (IFF) beacon on the RAF plane would have identified it as a friendly aircraft and distinguished it from an incoming Iraqi missile, the expert said.