But an Air Force program in the works may enable pilots to plow through just about any foe -- even an Iraqi sandstorm.
The solution is an onboard computer that digitally renders the pilots' surroundings when they can't rely on the real one to guide them. It's called "synthetic vision," and its backers are promising that the system will let pilots see in nasty weather, just like night-vision goggles let troopers roam around in the dark.
"There's no doubt in my mind that there's a tremendous military benefit to this technology," said Thomas Schnell, director of the University of Iowa's Operator Performance Laboratory, an experimental flight center. "As long as you could receive a GPS signal, you could fly using synthetic vision -- no matter what the weather."
Sandstorms included, he added.
Both the Air Force and NASA are trying out versions of synthetic vision. In recent tests, the Air Force's 412th Flight Squadron flew a modified C-135 transport plane -- nicknamed the Speckled Trout -- using the system.
NASA has committed $100 million over five years to develop synthetic vision as part of a larger effort to improve aviation safety. Its first full-fledged demonstration of the system will come in late May or early June, at the Wallops Island test flight center. The second will be in June or July, at the airport in Reno, Nevada.
With these tests pending, synthetic vision clearly isn't about to be deployed in Iraq. Too bad -- the U.S. military could have used it over the last few days.
"You would be able to use synthetic vision systems to effectively see through sandstorms," said Russ Parrish, chief scientist of NASA's synthetic vision project, "if you had a high enough resolution image of the area."
That assumes, of course, the dust doesn't choke your engine.
A few of the Army's Humvees have been able to creep through sandstorms by relying on satellite-based locators. Night-vision systems have boosted visibility to about 10 feet when sand kept soldiers from seeing their hands in front of their faces. And infrared sensors have provided images a bit further out. But these makeshift answers have only been marginally helpful.
"The particles that block your normal vision would block these sensors, too -- just on a different wavelength," said James Ratches, chief scientist of the U.S. Army's CECOM Night Vision and Electronic Sensors Directorate.
Synthetic vision avoids that problem by having a picture of the world stored on the plane. In 2000, the Space Shuttle Endeavour took detailed 3-D radar images of more than 80 percent of the earth's terrain. The Defense Department's National Imaging and Mapping Agency is now translating this data into digital, topographical maps. These shuttle maps could then be checked against public satellite images; double-checked against data in the Global Positioning System or Internal Navigation System; and triple-checked by radar, infrared or millimeter wave sensors.