Automatic Spar Assembly Tool 4

Electroimpact designed and manufactured an Automatic Spar Assembly Tool (ASAT4) for Boeing's C17 program. ASAT4 is based on the concept of "in jig" assembly with a vertical yoke assembly machine. This ASAT configuration was initially implemented for the Boeing 737 and 757 programs. ASAT4 however offers an unprecedented level of flexibility along with many new features for improved process speed and control.

ASAT4 consists of a vertical traveling yoke machine which straddles the spar fixtures. Two fixtures placed end to end form a system approximately 220 feet in length which is serviced by a single machine. This allows manual operations, e.g. load and unload, to be performed on one spar while the machine works in the adjacent cell. Each fixture can accept any of the six C-17 spars. Fixture reconfiguration between spars is completely automatic. The single three axis yoke machine, the E5000, travels the full system length. The yoke is simply supported on the side of a rigid gantry structure. The E5000 has completely redundant tool heads on both legs of the yoke. This permits drilling and fastener insertion from either side of the spar.