Multizone Inspection (MZI) is an ultrasonic inspection system that has been developed in response to FAA recommendations for improved inspection of titanium billet material. The system is capable of achieving &mesh;2 FBH sensitivity in billets up to 10 inches in diameter. Honeywell as well as other OEMs are interested in adopting this inspection technique in response to FAA recommendations and to improve the sensitivity of their inspection procedures. To achieve that goal an evaluation of the system capability and variability at the supply base is necessary. This paper summarizes the results of a round robin study conducted at the supply base to evaluate the variability of MZI for 8 inch‐diameter Ti‐6Al‐4V. It was found that on the average there is about 27&percent; amplitude variability and 38&percent; Signal‐to‐Noise Ratio (SNR) variability at each surveyed facility. It was also found that the variability from one facility to the other was on the average about 28&percent; in amplitude and 30&percent; in SNR. © 2003 American Institute of Physics