WASHINGTON, April 24 (UPI) -- In his last e-mail message home before he died, 30-year-old Navy pilot Lt. Nathan White described the challenges his F/A-18C would face over Iraq. One of his top concerns was avoiding American Patriot air defense missiles.
White, who graduated as the top pilot in his flying class, was shot down by a Patriot missile near Karbala, Iraq, on April 2, as he returned from a mission.
With more than 1,000 aircraft over Iraq every day, White described the chaos of launching from an aircraft carrier and flying into the war zone. After an hourlong briefing on his mission, he would climb into the cockpit and be catapulted off the deck, reaching 140 mph in two seconds.
Then he would navigate the system of "airborne highways" created by the military to keep planes from crashing into each other "and of course steer you clear of the army's Patriot batteries," White wrote.
It was not a joking reference. White's was the second plane shot down by a 17-foot-long, 2,000-pound Patriot missile. His was the third coalition plane targeted by the system within a 10-day span.
On March 24, a Patriot missile shot down a British Tornado, killing both crew members. One day later an American F-16 pilot fired on and disabled the Patriot system that targeted him.
The Army, Navy, Air Force and the United Kingdom are all investigating the "friendly fire" accidents and almost all data about them is now shrouded in secrecy for the sake of the inquiry.
Shortly after the British Tornado was shot down over Kuwait, a British commander announced his confidence that an accident would not happen again.
"The Americans have made a rapid and prudent re-evaluation of Patriot rules of engagement. I can categorically assure my crews that there is no danger of inadvertent engagement," Group Capt. Simon Dobb said.
According to White's father, Dennis, the Navy believes White's plane was hit with two Patriot missiles, one after another, in a technique called a salvo. It is one of three firing options automatically offered by the Patriot, according to Army documents, and is used to assure a kill.
It was a direct hit, apparently slamming directly into White's cockpit. The impact most likely caused White's plane to eject him. His intact parachute was found floating in Lake Karbala. The Navy believed for 10 days White had ejected over Karbala where an intense ground battle was raging and was either hiding or a prisoner.
White had flown over Iraq multiple times over the years from the USS Kitty Hawk, an aircraft carrier. He was accustomed to dodging Iraqi air defenses because of missions enforcing the southern no-fly zone.
"They had been dodging air defense for months, going into the no-fly zones. It was a no-brainer," Dennis White told United Press International this week. "But based on what they have found, once you are tracked by the Patriot, it's impossible to shake."
Lt. White, wearing night-vision goggles, was returning from his mission over Karbala. He radioed that he saw two missiles launched. Six seconds later he was dead.
The Patriot has not always been so effective. It made its combat debut in the 1991 Persian Gulf War, using specially adapted Patriot PAC-2 missiles that would target not just aircraft but Scud missiles. Iraq launched 88 Scuds during the Gulf War. They were clumsy, wobbling on an unpredictable flight path and even breaking apart as they landed.
According to Victoria Samson, an analyst with the Center for Defense Information, the Pentagon claimed immediately after the war that its forces shot down 41 of 42 Scuds targeted. Those estimates were later scaled down to 70 percent of the missiles shot at Saudi Arabia and 40 percent of those launched against Israel.
The General Accounting Office in 1992 said that the intercept rate was closer to 9 percent. Ted Postol, a professor at the Massachusetts Institute for Technology, reviewed the same data and said the intercept rate was closer to zero. Defense Secretary William Cohen said in January 2001 that "the Patriot didn't work," according to The New York Times.
The picture appears considerably different in Iraq this time.
According to U.S. Central Command, the Patriot engaged nine of 14 surface-to-surface missiles launched at Kuwait. It destroyed all of them. The others were on paths that had them land harmlessly in unpopulated areas.
Missile Defense Agency Director Lt. Gen. Ronald Kadish told a Senate committee April 9 that 24 Patriots have been launched so far: 20 upgraded PAC-2s and four PAC-3s. Kadish called the Patriot performance "very, very good" and "very encouraging."
At any one time the system can handle between 90 and 125 target tracks and is able to support up to nine missiles in their final phase of engagement, according to the Army.
There are a number of ways for the Patriot to determine the status of an aircraft as friendly. First, the craft will fly an established path or in an engagement zone that air defense crews know is populated by "friendlies." Second, the aircraft is outfitted with an electronic identification friend or foe transponder, or IFF, that would beam its identity to other friendly aircraft and ground units. Third, it can be identified with passive electronic queries –- essentially, acoustic profiles that indicate the make of the aircraft. There are other layers of protection, as well: the aircraft's voice radio connection to an airborne or ground controller, and its shape, speed and heading, all of which can be visually tracked or tracked by radar.
Patriot and other weapons systems have three standing conditions for firing. "Weapons tight," allows the crew to fire only when the system positively identifies an aircraft as hostile. "Weapons free," the loosest, allows a Patriot crew to fire at any target not positively identified as friendly. The strictest mode is "weapons hold," when the Patriot can only be fired in self-defense or with a specific order to do so.
At no time during the Persian Gulf War did the Patriots fire on any allied aircraft. The missile system was on "weapons hold" mode, according to published reports. There was a reason for such caution in the Persian Gulf War.
Just a few years before, in 1988, the military conducted an exercise called Green Flag. That exercise simulated a battle in which IFF system transmissions and radio transmissions were jammed. When fighter jets strayed out of established fighter engagement zones into missile engagement zones, Patriot batteries "fired on" friendly planes 50 percent of the time. When IFF was introduced back into the mix, that friendly fire rate dropped to 6 percent, according to retired Marine Maj. Jeffrey Chlebowski, who studied the Patriot friendly-fire history as part of a master's thesis for the Navy's post-graduate school.
The problems continued even after the Gulf War. In August 1993 the military conducted a test of the Patriot and other air defense systems to see what would happen in airspace dense with both friendly aircraft and air defenses. The results, according to a National Research Council report in 1996, were "disturbing."
"Attempts to coordinate air and (surface-to-air missile) intercepts in the same airspace led to unacceptably high levels of (simulated) fratricide," NRC reported.
Operational testing in 1999 of the radar system of the Patriot PAC-3 program showed a failure rate 2.4 times greater than expected –- a problem brought under control in later testing, according to Pentagon documents.
Prior to the introduction of the Patriot in 1986, U.S. aircraft and surface-to-air missiles kept themselves safe from each other by using separate "engagement zones." Aircraft provided anti-air defense, and surface-to-air missiles protected high-value targets, according to Chlebowski.
When the Patriot entered the fray, it vastly complicated the picture. It was a missile system with a long range that was specifically designed for air defenses. Its reach extended into traditional fighter engagement zones, putting those aircraft at risk.
Even with "physics-based" combat identification -– the acoustic signature of friendly aircraft -– IFF, and protected engagement zones, the friendly-fire results were still dismaying.
Military simulation experts separated one major part of the problem from the rest: the friendly-fire incidents caused by the Patriot system. Was there a procedural way to protect aircraft from the air defense system if IFF failed?
The simulated test found that friendly aircraft strayed off their expected flight paths while within range of a Patriot for anywhere from 30 seconds to out 79 seconds. Hostile aircraft all violated the "friendly" flight path by at least 90 seconds, according to a paper presented at the 1995 modeling and simulation workshop of the International Testing and Evaluation Association at White Sands Missile Range, N.M.
The test found that if Patriot crews waited 60 seconds after target acquisition before firing, the likelihood of fratricide would decrease by 86 percent without allowing any more hostile aircraft to slip by. That delay requires a "man in the loop," however, to put off firing long enough to allow positive visual identification.
IFF transponders can fail for a number of reasons; the Navy generally requires positive "mode 4" IFF checks before each flight of each plane that launches off an aircraft carrier. But even if Lt. White's transponder had failed or he had neglected to turn it on, he was flying close to another F-18 as a wingman to his squadron commander, his father told UPI.
"Even if he wasn't identifying, it still doesn't negate the fact that he was flying with another pilot, his squadron commander. His plane would have had IFF, too," Dennis White said. "Either his plane wasn't identifying either or the Army failed to identify."
The Patriot's IFF transponder processor is at the base of a massive, truck-mounted panel that also hosts the system's radar. The IFF processor has a history of being accidentally kicked and damaged by Patriot crews.
An Army maintenance flier shows a smiling cartoon radar warning operators to "keep their feet away from IFF system elements and the main array elements" which can cause them to fail.
The Patriot's IFF can be enabled, disabled or varied to reflect different parameters with a push button control, according to Army documents. The IFF determination is not limited to the transponder alone. It is also shaped by data on the target received from the battalion fire unit, from adjacent battalions, and from higher echelons.
The Patriot operators are supposed to go through several steps before firing. The individual target would be designated and queried with IFF. The system can call up the battalion data file on the unknown target, then display a flight track history. Satisfied it is a friendly aircraft, the operator can drop the target.
A critical point for pilots seems to be a handoff, which can happen a few to a dozen or more times during a mission. The National Research Council found that every time a pilot switches from one air controller to another as he moves on his flight path his plane is increasingly vulnerable to fratricide.
"Handoff problems," the NRC wrote in a 1996 report, "have been involved in such disparate incidents as the accidental helicopter shoot-down in Iraq and commercial aircraft accidents in terminal areas."
In his final e-mail, White said he would switch radio frequencies and air controllers 12 times en route to his target.
It is possible, however, that direct human error was not the cause. It is possible the Patriot system was in an automatic firing mode with no one at the controls to check the identity of White's plane.
The Washington Post reported a Patriot battery crew had taken cover from incoming artillery just before the second incident, when the Air Force F-16 was locked on by the fire-control radar. This left the Patriot in an automatic firing mode.
Dennis White said the Navy told him his son was flying over a fierce firefight the night he died. He told UPI he would not be surprised if the Patriot was in an automatic firing mode when his son was shot down.
"Being in an auto-response mode would be desirable from a ballistic missile point of view. They come in very fast with virtually no warning. There's no time to get people in the loop," a Pentagon official familiar with the program said. "But they could screen out or create a fence so no aircraft can be a target."
He explained, "An incoming ballistic warhead looks entirely different than a fighter jet. If these Patriots were in theater to defend against Scuds, there are all kinds of safeguards. You are not supposed to be shooting weapons without a positive ID."
Phil Coyle, a former Pentagon chief of operational testing, questions why Patriots were allowed to fire on any aircraft at all. U.S. Central Command reports that not a single Iraqi aircraft took off during the entire war.
"I want to know what they were doing targeting any aircraft," he said.
The Patriot system also has an override function which can force missiles aimed at friendly or questionable targets to self-destruct or protect individual targets, according to the Army. It is called an "engagement override" function: hold fire, which includes a destruct command to any missile in flight to the target; cease fire; and engage hold, which allows no automatic launches against the target.
Humans-in-the-loop are the most important means of protecting friendly aircraft in a battle, the American commander of ground forces in Iraq acknowledged Wednesday.
"What really makes all the difference in mitigating the risk of fratricide has nothing to do with technology. It has everything to do with the tactical discipline of units, of using the right fire support coordination measures, the right tactical graphics and the right weapons control status and discipline of formations," said Lt. Gen. Dan McKiernan from Baghdad in a video-teleconference with Pentagon reporters.
Friendly fire is not new to this war. According to the Army, U.S. forces killed their own in the Persian Gulf at a rate four times higher than in previous wars. Just why that's true isn't clear, though an Army doctrine paper suggests the war's short duration and the fast pace of operations, or simply the more lethal modern battlefield, as possible reasons.
"You are never, ever going to completely mitigate the risk of blue-on-blue fire. That's a danger we have in this profession that no amount of technology will ever completely erase," McKiernan said. "I don't know what the final numbers are going to look like, but my initial impression is that we have greatly reduced, given the tempo of these operations and the time of this campaign when you compare it to Desert Storm."
Dennis White said what's important now is determining why the Patriot shot Nathan's plane down, 10 days after the Patriot killed two British pilots, and after the Army had reviewed its operation to keep it from happening again.
"For the sake of others, that's important. I have no doubt they'll determine what the error was," he said.
Neither the Army nor the aircraft manufacturer Raytheon would comment on the incident.
Lt. Nathan White, who won his irreverent call sign "OJ" for his persistence during a particularly difficult refueling operation, flew into Iraq on his last mission with great confidence, according to his last e-mail.
"When it gets really hard, it's like they always say: You fall back on your training. Redundancy in training prepares you for those nights where your legs are shaking and you know that if you don't relax and get your refueling probe into the refueling basket, you are going to flame out and lose the jet," he wrote to his family. "When you find yourself in a defining situation where a difficult decision has got to be made, you will fall back on your training and come out a survivor.
"I wish you all the best. Love, Nate," he wrote.
White, 30, was laid to rest Thursday. He is survived by his wife Akiko and their three children, Courtney, Austin and Zachary. A trust has been created for them, and donations can be made through www.ltnathanwhitechildrensfund.org.