Due to the part size and technological limitations of the available assembly equipment, traditional wing manufacturing has consisted of a three stage process. Parts are first manually tacked together in an assembly jig, They are then removed from the jig, rotated horizontally and craned into an automated fastening machine. Finally they are removed from the fastening machines and craned to a third station where the manual tacks are removed and the parts are prepped for final wing box assembly.
With the advent of electromagnetic riveting (EMR) and the traveling yoke assembly machine this traditional approach has been replaced with single station processing. Wing panels and spars can now be automatically tacked together under continuous clamp up in their assembly jigs using EMR. This eliminates the requirement for disassembly, debur and cleaning required with the manual process. While the wing panels and spars remain rigidly held in their flying configuration by the assembly jig they are fastened with an articulated yoke. Tool tables are mounted to the bottom of a solid yoke to insure opposing head alignment. Assembly jigs are lined end to end to allow one machine to service multiple stations and further enhance productivity.
In addition to efficiency improvements this new process improves product quality. The elimination of multiple crane moves and the manual tracking process greatly reduces the potential in process damage to the components. Since the parts are held rigidly in their assembly jigs during the entire fastening process, final panel and spar definitions are improved. Further, the use of EMR riveting has been demonstrated to provide superior fatigue to conventional process.
Two recent case studies of this approach are presented. The E4000 assembly system went into production on the A320 program in early 1998. The E5000 spar assembly system, ASAT4, goes into production in mid 1998. These two system are evolutions of earlier systems introduced on the Airbus A340 and Boeing 767 programs respectively. These two systems include a number of new enhancements over past systems and demonstrate approaches to both high and low rate aircraft production.