9
battalion. They were in the dark. Their systems couldn’t connect to the larger network, depriving them of vital information. All they had was a radio.
But they were soldiers, and they soldiered on. Their job was to protect coalition troops against Iraqi missile attacks, and so they did. They sat in their command trailer, with outdated gear and imperfect information, and they made the call. When they saw the missiles, they took the shots. They protected people.
The next night, at 1:30 a.m., there was an attack on a nearby base. A U.S. Army sergeant threw a grenade into a command tent, killing one soldier and wounding fifteen. He was promptly detained but his motives were unclear. Was this the work of one disgruntled soldier or was he an infiltrator? Was this the first of a larger plot? Word of the attack spread over the radio. Soldiers were sent to guard the Patriot battery’s outer perimeter in case follow-on attacks came, leaving only three people in the command trailer, the lieutenant and two enlisted soldiers.
Elsewhere that same night, further north over Iraq, British Flight Lieutenant Kevin Main turned around his Tornado GR4A fighter jet and headed back toward Kuwait, his mission for the day complete. In the back seat as navigator was Flight Lieutenant Dave Williams. What Main and Williams didn’t know as they rocketed back toward friendly lines was that a crucial piece of equipment, the identification friend or foe (IFF) signal, wasn’t on. The IFF was supposed to broadcast a signal to other friendly aircraft and ground radars to let them know their Tornado was friendly and not to fire. But the IFF wasn’t working. The reason why is still mysterious.
It could be because Main and Williams turned it off while over Iraqi territory so as not to give away their position and forgot to turn it back on when returning to Kuwait. It could be because the system simply broke, possibly from a power supply failure. The IFF signal had been tested by maintenance personnel prior to the aircraft taking off, so it should have been functional, but for whatever reason it wasn’t broadcasting.
As Main and Williams began their descent toward Ali Al Salem air base, the Patriot battery tasked with defending coalition bases in Kuwait sent out a radar signal into the sky, probing for Iraqi missiles. The radar signal bounced off the front of Main and Williams’ aircraft and reflected back, where it was received by the Patriot’s radar dish. Unfortunately, the Patriot’s computer didn’t register the radar reflection from the Tornado as
an aircraft. Because of the aircraft’s descending profile, the Patriot’s computer tagged the radar signal as coming from an anti-radiation missile.
In the Patriot’s command trailer, the humans didn’t know that a friendly aircraft was coming in for a landing. Their screen showed a radar-hunting enemy missile homing in on the Patriot battery.
The Patriot operators’ mission was to shoot down ballistic missiles, which are different from anti-radiation missiles. It would be hard for a radar to confuse an aircraft flying level with a ballistic missile, which follows a parabolic trajectory through the sky like a baseball. Anti-radiation missiles are different. They have a descending flight profile, like an aircraft coming in on landing. Anti-radiation missiles home on radars and could be deadly to the Patriot. Shooting them wasn’t the Patriot operators’ primary job, but they were authorized to engage if the missile appeared to be homing in on their radar.
The Patriot operators saw the missile headed toward their radar and weighed their decision. The Patriot battery was operating alone, without the ability to connect to other radars on the network because of their outdated equipment. Deprived of the ability to see other radar inputs directly, the lieutenant called over the radio to the other Patriot units. Did they see an anti-radiation missile? No one else saw it, but this meant little, since other radars may not have been in a position to see it. The Tornado’s IFF signal, which would have identified the blip on their radar as a friendly aircraft, wasn’t broadcasting. Even if it had been working, as it turns out, the Patriot wouldn’t have been able to see the signal—the codes for the IFF hadn’t been loaded into the Patriot’s computers. The IFF, which was supposed to be a backup safety measure against friendly fire, was doubly broken.
There were no reports of coalition aircraft in the area. There was nothing at all to indicate that the blip that appeared on their scopes as an anti-radiation missile might, in fact, be a friendly aircraft. They had seconds to decide.
They took the shot. The missile disappeared from their scope. It was a hit. Their shift ended. Another successful day.
Elsewhere, Main and Williams’ wingman landed in Kuwait, but Main and Williams never returned. The call went out: there is a missing Tornado aircraft. As the sun came up over the desert, people began to put two and two together. The Patriot had shot down one of their own.
U.S. Army Patriot Operations The Patriot air and missile defense system is used to counter a range of threats from enemy aircraft and missiles.
The Army opened an investigation, but there was still a war to fight.
The lieutenant stayed at her post; she had a job to do. The Army needed her to do that job, to protect other soldiers from Saddam’s missiles. Confusion and chaos are unfortunate realities of war. Unless the investigation determined that she was negligent, the Army needed her in the fight. More of Saddam’s missiles were coming.
The very next night, another enemy ballistic missile popped up on their scope. They took the shot. Success. It was a clean hit—another enemy ballistic missile down. The same Patriot battery had two more successful ballistic missile shootdowns before the end of the war. In all, they were responsible for 45 percent of all successful ballistic missile engagements in the war. Later, the investigation cleared the lieutenant of wrongdoing. She made the best call with the information she had.
Other Patriot units were fighting their own struggle against the fog of war. The day after the Tornado shoot down, a different Patriot unit got into a friendly fire engagement with a U.S. F-16 aircraft flying south of Najaf in Iraq. This time, the aircraft shot first. The F-16 fired off a radar-hunting AGM-88 high-speed anti-radiation missile. The missile zeroed in on the Patriot’s radar and knocked it out of commission. The Patriot crew was unharmed—a near miss.
After these incidents, a number of safety measures were immediately put in place to prevent further fratricides. The Patriot has both a manual (semiautonomous) and auto-fire (supervised autonomous) mode, which can be kept at different settings for different threats. In manual mode, a human is required to approve an engagement before the system will launch. In auto-fire mode, if there is an incoming threat that meets its target parameters, the system will automatically engage the threat on its own.
Because ballistic missiles often afford very little reaction time before impact, Patriots sometimes operated in auto-fire mode for tactical ballistic missiles. Now that the Army knew the Patriot might misidentify a friendly aircraft as an anti-radiation missile, however, they ordered Patriot units to operate in manual mode for anti-radiation missiles. As an additional safety, systems were now kept in “standby” status so they could track targets, but could not fire without a human bringing the system back to “operate” status.
Thus, in order to fire on an anti-radiation missile, two steps were needed:
bringing the launchers to operate status and authorizing the system to fire
on the target. Ideally, this would prevent another fratricide like the Tornado shootdown.
Despite these precautions, a little over a week later on April 2, disaster struck again. A Patriot unit operating north of Kuwait on the road to Baghdad picked up an inbound ballistic missile. Shooting down ballistic missiles was their job. Unlike the anti-radiation missile that the earlier Patriot unit had fired on—which turned out to be a Tornado—there was no evidence to suggest ballistic missiles might be misidentified as aircraft.
OBSERVE ORIENT DECIDE ACT
What is it?
Whose is it?
Radar detects and classifies object Humans apply outside information and context
Is it hostile?
Is it a valid target?
Establish situational awareness
Apply rules of engagement
Engage?
Decision whether or not to fire
Manual mode (semi-
autonomous):
Human operator must authorize engagement or system will not fire Auto-fire mode (supervised autonomous):
System will fire unless human operator halts engagement
System fires and missile maneuvers to target
Human operator can choose to abort missile while in flight
Patriot Decision-Making Process The OODA decision-making process for a Patriot system. In manual mode, the human operator must take a positive action in order for the system to fire. In auto- fire mode, the human supervises the system and can intervene if necessary, but the system will fire on its own if the human does not intervene. Auto-fire mode is vital for defending against short-warning attacks where there may be little time to make a decision before impact. In both modes, the human can still abort the missile while in flight.
What the operators didn’t know—what they could not have known—
was that there was no missile. There wasn’t even an aircraft misidentified as a missile. There was nothing. The radar track was false, a “ghost track”
likely caused by electromagnetic interference between their radar and another nearby Patriot radar. The Patriot units supporting the U.S. advance north to Baghdad were operating in a nonstandard configuration. Units were spread in a line south-to-north along the main highway to Baghdad instead of the usual widely distributed pattern they would adopt to cover an area.
This may have caused radars to overlap and interfere.
But the operators in the Patriot trailer didn’t know this. All they saw was a ballistic missile headed their way. In response, the commander ordered the battery to bring its launchers from “standby” to “operate.”
The unit was operating in manual mode for anti-radiation missiles, but auto-fire mode for ballistic missiles. As soon as the launcher became operational, the auto-fire system engaged: BOOM-BOOM. Two PAC-3 missiles launched automatically.
The two PAC-3 missiles steered toward the incoming ballistic missile, or at least to the spot where the ground-based radar told them it should be.
The missiles activated their seekers to look for the incoming ballistic missile, but there was no missile.
Tragically, the missiles’ seekers did find something: a U.S. Navy F/A- 18C Hornet fighter jet nearby. The jet was piloted by Lieutenant Nathan White, who was simply in the wrong place at the wrong time. White’s F-18 was squawking IFF and he showed up on the Patriot’s radar as an aircraft. It didn’t matter. The PAC-3 missiles locked onto White’s aircraft. White saw the missiles coming and called it out over the radio. He took evasive action, but there was nothing he could do. Seconds later, both missiles struck his aircraft, killing him instantly.