Pacific Rim customers account for approximately 75 percent of Boeing’s large aircraft orders. Therefore, when heavy economic activity and growth began to occur in the region, Boeing knew that it was time to build a new mega-liner. This is big airplane country – the bigger the airplane, the better, declared James F Chorlton, vice president of international sales for Boeing. Customers are asking, Are you going to make a bigger one? When are you going to make it, and how big will it be?
Boeing’s answers: real big. Boeing’s latest accomplishment, the Boeing 777 twin engine jetliner, boasts an empty manufacturer’s weight increase of 57% over its predecessor, the 767. With more than 3 million individual parts, the overall cost of the development and production of the 777 fell somewhere in the neighborhood of $10 to $ 12 billion. With such a massive financial investment, both Boeing and its customers wanted to be sure that the plane fly, without the need for modification, right off the assembly line.
Boeing therefore relied extensively on the use of computer aided design to develop a three dimensional computerized modeling system. CAD’s ability to model in solids allowed Boeing to design everything from the 777’s main cabin to the tools that would be used to perform maintenance on the craft. More than 1,700 engineers worked together on the project to produce parts and tools would work together perfectly their first time out.
Here is how the CAD works, First, a proposed aircraft component is generated by a computer. Then a digitally generated “human” tries out the component. In Boeing’s case, this virtual test subject is drawn from any of 12 population sets, each of which contains thousands of people measured according to more than 35 dimensions. Utilizing these measures, a wide variety of human body styles can be generated and then used to test the aircraft’s ergonomics. For example, the designers of the 777 discovered through this CAD technique that a mechanic would have difficulty reaching the 25 pound chiller fan above the main cabin. Standing on a ladder and reaching through an access hatch the mechanic would be severely overbalanced and likely to fall. Using the CAD system, the designers were able to reconfigure the access hatch to eliminate the problem. The design, construction, and modification of the hatch all took place on the computer, without the need to change a single screw.
CAD also enables tool designers to receive constantly updated, three dimensional information from engineers. Before sending tool specifications to the designers, engineers previously had to manually make tracings of the aircraft parts around which tools were to be built. With CAD, the part is represented in three dimensions in the actual location it will occupy on the aircraft. The designer can then create a tool specifically for use on that part. In additions, the designer can even check the tool’s size against its allotted storage space.
Since CAD programs can be customized to provide simulations of virtually any aspect of design, production, or use, Boeing decided to employ CAD in areas other than maintenance as well. Computer generated humans also stood in for pilots, flight attendants, and passengers. In the cabin, for instance, factors such as controls, seating and leg room must be designed. The digital human used to test the specifications could be programmed to simulate someone anywhere from 5 feet, 2 inches, to 6 feet, 4 inches in height. Similarly, lavatory seats were designed using digital humans who simulated an even wider variety of physical measurements.
CAD was also effective in improving the actual construction of the 777. Assembly line workers were able to receive enhanced work instructions that included detailed graphics and explicit instructions as to how to assemble the plane. Graphics generated computers enjoy the added advantage of being able to be altered easily, in the event that design changes should occur.
Overall, CAD has redefined the very nature of building an aircraft. In the past manufacturing was at the end of the pipeline recalled Dale M Hougardy, vice president of Boeing’s operations. With this approach, from day one we started with the manufacturing plan. The plan was developed as engineering matured. This is concurrent engineering in action. The ability to incorporate producibility factors as the design matures, instead of only upon completion, resulted in sharply reducing the cost of manufacturing the 777.
Utilizing CAD technology has enabled Boeing designers to save the company both time and money. A reduced need for modifications and repair will also improve the 777’s overall efficiency and profitability. Moreover, greater customer satisfaction is likely to result from improvements such as the enhanced tool storage and easier maintenance. Through CAD technology, Boeing has developed the 777 in less time and money and with greater quality and safety.