Newsday April 23, 2003
Use of Patriot Is Questioned
'Friendly fire' deaths blamed on complex missile system
By Charles Piller
The Patriot antimissile system, hailed by U.S. officials as one of the high-tech success stories of the Iraq war, also inflicted some of the most damaging "friendly fire" of the conflict.
The Defense Department has acknowledged that the antimissile system was involved in the downing of two allied warplanes, resulting in the deaths of three airmen. The two aircraft - one American and one British - are the only confirmed cases of planes being shot down during the war. Another plane narrowly escaped becoming the third victim of the Patriot system.
"The Patriot should have been stood down until they figured out why it was shooting down planes," said Joseph Cirincione, who directed a congressional assessment of the Patriot after the 1991 Persian Gulf War. "It's bad enough that it happened once. It's unconscionable that it happened again."
The sophisticated ground-based anti-missile system rocketed to prominence in the 1991 Persian Gulf War, gaining the nickname Scudbuster as it seemed to obliterate some of the Iraqi long-range ballistic missiles heading for Israel and Saudi Arabia. But after the war, congressional and independent analyses concluded that the Patriot may actually have missed every Scud it targeted.
The friendly-fire incidents in the current war have raised concerns that the long-troubled system is still too complex and poorly tested to be deployed.
The military maintains that the system is vastly improved since 1991. It has spent $3 billion on the Patriot's missile and tracking technologies, and, during the current campaign U.S. Central Command in Qatar said the system destroyed all nine Iraqi missiles it targeted.
"We are well along in our goal of demonstrating its reliability," Lt. Gen. Ronald Kadish, director of the Pentagon's Missile Defense Agency, told a Senate Appropriations Committee panel April 9. He called the Patriot's overall performance "very good."
But when asked whether the downing of the two allied jets and the near shooting of another were caused by human or mechanical error, Kadish said, "I think it may be both." He added, "There are investigations under way into each of the three incidents. I think we should wait until they're complete before we begin jumping to conclusions as to where the fault lies."
The Patriot attacks on allied planes were particularly puzzling given that throughout the war, no Iraqi aircraft were aloft.
"Why were the Patriots even shooting at aircraft?" asked Philip Coyle, former assistant secretary of defense and director of operational testing and evaluation for the Pentagon. "We ruled the skies in Iraq, so almost by definition any aircraft up there was either ours or British."
The Patriot system, designed in the 1970s to shoot down enemy aircraft, should have been able to distinguish between relatively slow-moving planes and speedy rockets fired by Iraqi forces, Coyle said.
"If they can't tell the difference between a missile and an airplane, then they need much more restrictive rules of engagement," he said.
Experts said such friendly-fire episodes stem from the long-range, split-second nature of modern war. A compounding factor is the enormous complexity of the Patriot system, which makes it vulnerable to mechanical, computer and human error.
The Pentagon will look closely at the Patriot's automated engagement mode, in which the system's radar may lock onto a target without operator intervention, as a possible culprit, Coyle said.
At the Senate hearing Kadish said that possible system defects or a breakdown of the "identification friend or foe" system - a primary way to identify aircraft in battle - also will be scrutinized.
All aircraft are equipped with IFF transponders that, when polled by a friendly ground station, will respond with codes to avoid being targeted as an enemy. Something as simple as a broken or inactivated transponder could trigger a friendly-fire incident. But given that there were three separate cases, such errors seem unlikely.
Theodore Postol, a physicist at the Massachusetts Institute of Technology and co-author of an influential study criticizing the Patriot performance in the 1991 Gulf War, suggests that the problem may lie with the way the Patriot system interpreted IFF signals. With the Iraqi air force grounded, he said, the return signal "is never going to be a 'foe,' so there's no reason ever to fire at an airplane," he said. "These systems apparently didn't work."
Soldiers operate the Patriots using computer displays that show digital maps of the sky. Icons indicating friend, foe or unknown move across the screen, much as in an air-traffic control system. When a target such as a jet, robotic drone or missile is confirmed, one or more intercept missiles are launched.
Tim Carey, vice president of the Patriot product line at Raytheon Corp., the prime contractor, said the system is designed to distill an accurate picture from complex and confusing information. For example, each battery relies on two operators to handle the high flow of battlefield data. "When things are hot" - that is, if a battle is raging - "both soldiers have exactly the same display up, and they will work together to confirm the targets," Carey said.
The Army's enthusiasm for the Patriot has been bolstered by the system's seemingly perfect record of nine life-saving missile kills in the Iraq war. But skepticism of such claims is running high because of the Patriot's history of exaggerated accomplishments.
In the 1991 Gulf War the system also seemed to perform almost flawlessly. The Army said that Patriots intercepted 45 of the 47 Scuds targeted. But MIT's Postol analyzed video footage of 28 of those cases and found that not a single Scud warhead had been destroyed. In fact, the Patriots often missed the target by hundreds of meters.
Postol's results were confirmed by a House Governmental Operations Committee study led by Cirincione in 1992. "When we scrubbed the data, it turned out that the best evidence supported successful intercepts of between zero and four Scuds," Cirincione said.
Ultimately, the Army reduced its claims from 45 to 24 warhead kills.
Where It Might Have Failed
Though the Patriot missile system recently was upgraded to improve its accuracy, it locked on to friendly aircraft in three cases during the war.
1. Friendly Aircraft
Plane transmits ''identification friend or foe (IFF)'' signal to ground defenses so it would not be targeted.
Possible Failure
IFF transmitter might havebeen broken or deactivated, though the chances of that happening in three cases is remote.
2. Radar
System tracks the incoming object.
3. Control Station
Operators receive radar data and check airborne object's IFF signal to determine whether it is a missile or aircraft, friend or foe.
Possible Failure
Operators might have incorrectly judged the aircraft as hostile, or the system's auto mode might have engaged it without human input.
4. Missile Fires
Patriot seeks out the target.
SOURCE: GlobalSecurity.org; Los Angeles Times
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