On-Machine Inspection for Rotorcraft Manufacturing

The inspection step of rotorcraft component fabrication is critical to the manufacturing process. Inspection is essential for demonstrating that component quality meets engineering requirements and tolerances. Engineering specifications often require components to undergo coordinate measuring machine (CMM) inspections more than once during manufacturing. Off-line CMM inspection can introduce lengthy delays due to CMM backlogs and/or operator availability. The ability to perform inspections while the manufactured component remains in-position (on the machining platform) presents an opportunity to eliminate set-up time, reduce manufacturing span and lower inspection costs. The capability, referred to as On-Machine Inspection (OMI), has been implemented at Bell Helicopter on a large machining system to inspect several military and commercial composite components. An innovative calibration artifact and validation method is described. The approach ensures high inspection integrity and allows for rapid manufacturing resolution when data anomalies occur. The use of OMI on a main rotor yoke has resulted in a dramatic reduction in manufacturing span and inspection duration.