During the co-curing process of composite aircraft structure

random position error of I-beams is diffi cult to be avoided

besides

position error exists during installation . As a result

both rivet holes on the I-beams and holes on single-surface curve skin are diffi cult even impossible to be drilled automatically. To realize the process of NC drilling

on-line inspecting position error of structure feature points and amending existing NC programs are proposed. The principle of position error measurement of feature points

the numerical error model and the strategy for amending the NC programs are presented. This work provides a solid foundation for the NC machining of certain composite structures on aircraft.