Though the F-117 stealth bomber, the Tomahawk cruise missile, and the laser-guided bomb probably garnered the majority of the public attention and accolades during the first Gulf War air campaign, true aficionados know first shots fired in the war came not from any type of Air Force jet but from two quarters of Army attack helicopters in the Iraqi desert. Their attack on two early warning radar stations, code-named EAGER ANVIL, is yet another example of the apparent transformation that GPS enabled. Led by Air Force special operation helicopters, the joint team known as Task Force Normandy flew more than twenty miles into Iraq, across mostly featureless desert on a moonless night to destroy two radars and open up a gap in the Iraqi air defense network for the Coalition’s air forces to exploit.
The mission’s origins were somewhat convoluted. What began as a planned ground assault by Army special forces infiltrated over the border on foot gradually morphed into a joint helicopter attack by Air Force special operations helicopters and AH-64 Apache attack helicopters from the Army’s 101st Airborne Division. The mission couldn’t be handed over to the Apaches alone because AH-64’s Doppler radar navigation system was, as one aviation officer put it, only “a ball park navigator” that would drift 300–500 meters in a two-hour flight (GAO/OSI-93-4, p.55).
The Air Force’s MH-53J Pave Low III helicopters, on the other hand, had one of the most impressive navigational packages in the US military. What had began as a series of improvements to the Air Force’s combat search and rescue (CSAR) helicopters during the Vietnam War had in the subsequent twenty years become the Air Force’s premier rotary special operations capability. When the Pave Low III went into service in 1979, it had a precision navigation system that included terrain following/terrain avoidance radar, a forward-looking infrared (FLIR) sensor, and a combination Doppler radar and inertial navigation system connected to a projected “moving map” display. The upgrade to the Pave Low III Enhanced configuration in the late 1980s gave the Pave Low community some of the first GPS receivers in the military. Major Ed Reed, one of the program managers, recalled that:
“I went to the first GPS meeting. I was a junior major there and everybody listed all of the aircraft that were going to get GPS and . . . every fighter was covered, every bomber was covered. And then some line in the nineties, the H-53 was going to get it. Wrong answer! I said, ‘Sorry, I’ve got a FAD-1 so I move to the front of the line.’ They said, ‘You can’t do that. We’ve got this list!’ I said, “You’d better call this office and find out if that’s going to be your list at the end of the day. So later I got a nice phone call. They said, ‘You can have the first boxes off the line.’ I said, ‘That would work just fine.’” (On A Steel Horse I Ride, p.229)
Because of this, Task Force Normandy paired four Pave Low helicopters with eight Apaches. Ten miles out from the targets, crew on board the Pave Lows would drop clusters of chemical lights. The Apaches would update their Doppler navigation systems as they flew over the lights, then close in their targets and destroy them with laser-guided Hellfire missiles, rockets, and gunfire.
Despite its challenging nature and the uncertainty surrounding it, the mission went smoothly. After four minutes, twenty-seven Hellfire missiles, 100 rockets and 4,000 rounds of 30mm ammunition, both radar sites were destroyed. No aircraft were lost.
Task Force Normandy’s mission is a great encapsulation of both the contribution GPS made to the Gulf War and the limits of that contribution. GPS made navigation on the mission more or less trivial (though I’m not sure it would have been impossible with the pre-GPS Pave Low navigation computer), but the capability was tied to those helicopters rather than a broader network. To pass navigational information to the accompanying Apache’s, Task Force Normandy had to resort to a supremely low-tech solution.
The problem was that while GPS was global, it was not universal. A GPS receiver knew its location to within ten meters, but that knowledge only had meaning in conjunction with other, less precise information – like maps or the navigational systems on other aircraft. The problem was particularly apparent for search and rescue, the primary mission for the Air Force special operations force. As Lieutenant Colonel Richard Comer, the commander of the squadron which flew the Pave Low in Desert Storm, described it:
We were dealing with coordinates from somebody who was flying out there and doing acrobatics dodging missiles with an INS or Doppler, [which is why] his coordinate wasn’t going to be close to where that person was on our GPS. We didn’t know that. We thought that . . . we should just be able to fly to it and be able to hover above the guy and be able to drop the hoist down through the fog and pick him up. We didn’t know. (CSAR in Desert Storm, p.153)
Even small differences in the systems of coordinates GPS used could make the difference. B-52 bombers that initialized their inertial navigation systems at Diego Garcia using coordinates from WGS72 datum dropped their bombs 400–600 feet away from targets whose coordinates were set using the WGS84 datum. The full value of global positioning, it appeared, only appeared when friend and foes had commensurable a global position.