Aircraft manufacturers have a love-hate relationship with high technology.
On the one hand, being on the cutting edge just doesn't pay. "We could build a plane for a 500-mile mission with half the weight, twice the fuel efficiency and could go three times as fast as the MD-95," McDonnell Douglas Director Jerry Callaghan says in reference to the company's new 100-seat airplane. "But it will only last for one flight."
Or, as Robert Hammer, a Boeing vice president responsible for re-engineering the company's design and manufacturing processes, puts it: "The military is doing stuff like stealth technology, but who needs a stealth commercial airplane?"
At the same time, though, a wide range of new technologies is revolutionizing the way airplanes are built. Computer and communications tools are cutting production costs, raising quality and, perhaps most important, making possible a whole new style of global aircraft manufacturing.
With improved global computer networks, McDonnell Douglas and Boeing can work effectively with partners and suppliers all over the world--not to mention with each other, now that they have agreed to merge.
At the Long Beach-based Douglas Aircraft division of McDonnell Douglas, engineers are working with companies in South Korea, Italy, Germany, Taiwan, Japan and Israel to design and build the MD-95, which is scheduled for delivery in 1999. Grace Robertson, who is in charge of advanced program development for commercial aircraft at Douglas, calls these partners "electronic immigrants."
Engineers using computer-aided design programs type in commands and click their mouses to build three-dimensional models of airplanes and all their components. The computer can compare designs to check whether two parts will fit together snugly, eliminating the need for building physical models out of plastic or clay. The time and money savings are on the order of 40%.
The CAD software makes it possible for workers in different countries to collaborate on the same engineering assignment. Instead of shipping parts, they can send electronic models back and forth in an instant. In the future, says Ernie Valdiva, Douglas' general manager of assembly tooling, workers will piece together electronic models of parts using virtual reality displays.
Boeing brought CAD technology to the fore by using a program called CATIA--short for computer-aided, three-dimensional, interactive application--to design its new wide-body 777 plane, which can carry 328 passengers and fly up to 8,320 miles without refueling. Boeing engineers are now using CATIA to design upgrades for the company's older lines.
McDonnell Douglas favors a similar program called Unigraphics, which is being phased into all airplane development at Douglas Aircraft. Engineers use the program to conduct a stress analysis and check the airflow over a plane before any parts are even built.
A closely linked development is the rise of computer-aided manufacturing, in which pieces of a plane are milled according to the instructions of a computer. The resulting parts--which can be designed anywhere--are more precise and consistent than those made with traditional machine tools.
At Boeing, the fuselage assembly improvement team is using these technologies to produce parts that fit together as easily as Legos. The design software tells the manufacturing software where to drill a small number of reference holes in each part. Assemblers put the parts together by lining up the reference holes and plugging them with rivets.
Paul H. Nisbet, president of JSA Research Inc., an independent aerospace research firm in Newport, R.I., estimates that switching to these manufacturing techniques will shave as much as $15 million off the cost of building a 747.
Researchers at Douglas Aircraft are improving on computer-aided manufacturing technology so they can build very large parts out of super-hot lithium. Bigger parts are stronger, need less assembly and are more precise.
One of the trickiest steps in the manufacturing process is lining up the major sections of the airplane's fuselage, wings and tail. New alignment systems based on lasers are proving to make the task much easier.
The systems work by shooting laser beams to a series of targets spread out on the pieces of the airplane that are being joined together. When the laser beams bounce back to their source, a computer measures the angle of return and calculates the exact position of the targets. Then the computer compares where the targets are to where they are supposed to be, and assembly workers make the adjustments.
Using laser alignment, the smooth surface of a Boeing plane varies by only 0.023 inch (about the thickness of a playing card) over the length of the plane from tip to tail--a distance of more than 200 feet. With traditional tools, the variation is closer to half an inch.