A ROBOT INSPECTOR FOR AIRPLANES Aging jetliners suffer from skin cracks and loose rivets. A self-propelled gadget called ANDI could soon help locate any danger spots.

(FORTUNE Magazine) – It may look like a cubist bed frame with suction cups for feet, but ANDI could come in just as handy as its robot cousin R2D2 in Star Wars. Engineers at the Carnegie Mellon Research Institute designed ANDI -- short for automated nondestructive inspector -- to ease the chore of checking airplanes for tiny but potentially fatal flaws in their thin aluminum skin. When it's perfected in three to five years, at a cost of some $2 million, it should help keep the world's aging fleet airworthy. ANDI owes its creation to the Aloha Airlines Boeing 737 that peeled open in midair like a can of sardines in 1988. One flight attendant was killed, but the plane landed safely. The cause: metal fatigue, the airplane equivalent of old age. Since financially pressed airlines are rebuilding older planes instead of scrapping them, hairline cracks and loose rivets are becoming more common. They are also extremely difficult to spot with the naked eye. Today human inspectors on specially constructed scaffolds pass electronic sensors over the fuselage. The job is tedious, and concentration can easily flag, so the Federal Aviation Administration gave Carnegie Mellon a contract to develop an automated helper. Like today's hand-held devices, ANDIs will have sensors that use electrical ! currents to locate hidden flaws X-ray fashion. The sensor induces a circular electrical field in the plane's metallic skin. A tiny gap between a rivet and the skin is normal, and produces a characteristic pattern. An overlarge gap or a crack in the skin changes the shape of the field, alerting the inspector to a defect for mechanics to repair. ANDI's job is to get the sensor in exactly the right place. Lipstick-size cameras mounted fore and aft will give it a field of view the size of a jumbo photo print -- about four by six inches. Image-processing software in a computer workstation, joined to ANDI by an umbilical cord, will recognize rivets and guide the robot along them. Motors will move the sensor back and forth along ANDI's two-foot spine, or from side to side. A camera mounted next to the sensor will allow exact positioning; readings from the sensor will flash up on the computer screen. ANDI will also mark questionable spots with washable paint. Suction cups and a complex pneumatic system will help ANDI walk all over the plane like a fly (see diagram), even upside down . If ANDI loses its grip, a lifeline will keep it from falling to its death. As they build ANDI, the Carnegie Mellon engineers are paying frequent visits to USAir's nearby Pittsburgh hub to get feedback from future users. ''ANDI is not intended to replace the inspectors,'' says Melvin Siegel, a senior Carnegie Mellon robot scientist. ''It's a tool for their tool kits, designed to make their job safer, more effective, and more pleasant.'' And presumably to give fretful fliers a bit more peace of mind.