In the clean, cavernous factories where aircraft are built, the jets-in-progress get careful, precise attention at every station along the line. If a robot can perform this kind of demanding work, it can work almost anywhere.
There are no more than 5,000 industrial robots working in the United States today, and most of them are so simple-minded that they have to be led by hand through every step of their basic tasks. They work on assembly lines like those in auto plants, where they can do simple bits of work over and over.
But the most sophisticated robots are likely to get their first jobs in the aerospace business.
''Either we make (advanced robotics) pay in aerospace,'' says Jerry Saveriano , a factory automation consultant, ''or we lose out.'' The US is losing the robotics industry now to the Japanese, who generally are regarded as the world leaders in the field, experts say.
Building airplanes is not the kind of work ordinary robots are used to. Aerospace factories produce very expensive parts very slowly - sometimes two or three a month - and tooling accuracy sometimes runs to 5/1000 of an inch and less.
''It's tough, tough work'' for which to build robots, Mr. Saveriano avers. ''Very unprofitable.''
But the exacting work requirements are what make the aerospace industry important to robot development. In the last several years, aerospace companies have moved to the cutting edge of robotics applications: testing the most advanced robot systems and putting them to work.
The most advanced robots are smart (can take complex instructions from a computer); have keen senses (use vision systems or pressure sensors that assimilate touch); and have good coordination (can use different tools).
They are expensive and, as workers, they lack experience. But this industry is accustomed to expensive engineering projects. Aerospace companies already have the engineers on board, and they have sophisticated computer-aided design and manufacturing equipment. In addition, building a new line of aircraft requires an aerospace firm to undergo tremendously expensive retooling. Adaptable robots offer a chance to save some of this cost.
More than that, aerospace companies have the US Air Force. The Air Force has its own reasons for wanting to keep American aircraft-building at its most efficient, flexible, and consistent in quality. It supports that effort with development contracts.
For example, Northrop - which builds the F-18 and F-20 fighter jets, among others - has collected about $3.5 million from the Pentagon for automation projects in the past five years. That figure is roughly equal to what the company has spent of its own money.
The most productive jobs for advanced robots, says 1st Lt. Gordon Mayer of the Air Force materials laboratory's robotics program, will be in assembling parts. Some early steps:
* McDonnell-Douglas - one of America's largest aircraft manufacturers - developed a computer language for controlling robots as part of an Air Force contract to develop a robotic riveter.
* Lockheed has a robot that positions fasteners on the plane and rivets them. It works freehand, without mechanical guides, from the instructions programmed into it, and can meet the 30/1000-inch tolerances demanded.
Lockheed engineers already have bought a three-dimensional vision system to make its riveters more flexible, and plan to use two robots working together on the job. The company is competing for an Air Force contract for this step.
* Northrop has a robot arm with a flat vacuum head that picks up thin sheets of graphite composite - a Fiberglas-like material beginning to replace metal for some parts of airplane skins - and places them together for lamination. Northrop is tripling the size of its almost entirely automated ''factory of the future'' next month.
''They (robots) just don't know how to make a mistake,'' says Tom Rooney, Northrop vice-president in charge of development of the factory of the future. Northrop's robot made 500 graphite rudder skins last year. ''What really won over the shop people was that there wasn't a single error.''
A centerpiece Air Force contract now is for intelligent task automation. Honeywell is developing a micromanipulator and lightweight, force-sensing fingers. Altogether, this new equipment should be able to assemble a complex, small microswitch when complete.
Martin Marietta Corporation is competing for the demonstration phase of this contract. It is working on a system with three-dimensional vision, some degree of mobility, two interacting arms, and control through artificial intelligence.