CAMP AS SAYLIYAH, Qatar -- Coalition forces suffered their first confirmed "friendly fire" deaths of the Iraq war Sunday when a U.S. Patriot missile battery downed a British fighter jet near the Iraqi-Kuwaiti border, killing the two fliers on board.
Military analysts said the downing was rare, because the Royal Air Force Tornado GR4 would have been outfitted with a transponder -- an electronic signal device identifying itself as a coalition military aircraft.
The shootdown was a blow for Britain, which had suffered 14 dead in accidents: the crash Friday of a CH-46 Sea Knight helicopter that killed eight and a collision Saturday of two British Royal Navy helicopters that killed six.
Five American servicemen were killed in those incidents.
The Tornado was returning from operations in Iraq when it was targeted by a U.S. Patriot missile battery, the British military said. The Royal Air Force base at Marham, in Britain, confirmed the two crew members were killed.
Over Iraq, the fighter had been taking part in strikes that destroyed Republican Guard forces outside Baghdad, U.S. Brig. Gen. Vincent Brooks said in Qatar.
"I have to say it is not the beginning that we would have preferred," said Group Capt. Al Lockwood, spokesman for British forces in the Persian Gulf.
But he added, "This is not training, this is war. And we expect tragically, occasionally that there are accidents."
As warfare has become more reliant on precision-guided weapons, the likelihood of such incidents diminishes. But even if the technology were foolproof, the humans who use it remain vulnerable to mistakes.
"There are so many layers of information on all the layers of the battlefield," said Michael Donovan, a research analyst with Washington's Center for Defense Information. "Complex systems unfortunately tend to break down, you can count on it."
In Sunday's downing, Air Force Gen. Richard Myers, chairman of the U.S. Joint Chiefs of Staff, told ABC television that "procedures and electronic means to identify friendly aircraft and to identify adversary aircraft ... broke down somewhere."
"Central Command is looking into that as we speak. Again, it's a terrible tragedy and our hearts go out to the crew members," Myers said.
Paul Beaver, an independent military analyst formerly with Jane's Defense Group, said there was "99 percent no excuse" for shooting down a friendly aircraft.
Like all allied aircraft, the Tornados have an IFF, or "identification friend or foe" system compatible with all member countries of the coalition. The IFF, also used in civil aviation, sends an automatic response when a radar system queries it.
The Tornado's response "should be sufficient to stand down the (Patriot) system," he said. "The aircraft could have switched its IFF off if it had been returning, having been involved with some enemy action," or because of a technical failure, Beaver said. But in that case it should have been flying in a secret protective air corridor.