McDonnell Douglas Helicopter Company recently undertook a study to determine the actual simulator hardware time delay in all the simulators. It also investigated the effect of time delay on pilot performance and his aircraft evaluation in an engineering design environment. This paper describes the system architecture, techniques of measuring thruput delays, and initial study results. The average simulator delay was 87 milliseconds for the simulator with conventional flight control with the host computer running at 60 Hz. The average simulator delay was 101 milliseconds for the simulator with digital flight control system with the real time host executing at 30 Hz. The first value is less than those reported in the open literature for most of the engineering and training simulators while the second value is on par with the state-of-the-art systems in the industry. The second phase of the study involved systematically varying the simulator delays so that data on the effect of time delay could be collected and used as a useful parameter in aircraft/simulator design. Pilot performance was recorded and subjective evaluations in the form of Cooper-Harper ratings were also obtained. Analysis of pilot performance did not provide any dramatic changes due to increased simulator delays but did show that the pilot control activity increased in the low speed, high gain tasks. It was found that with increased time delay the Cooper-Harper rating increased indicating degradation in perceived handling qualities. However, for the type of helicopter simulated, there was not a definite time delay at which the ratings changed abruptly. This indicates that for engineering design purposes while it is desirable to keep the delay to the absolute minimum, there may be sufficient flexibility in the design of the simulator to permit cost/capability trade-offs. However, this needs to be further validated by additional tests that introduce pilot distractions (such as gusts) and force the pilot to increase his closed loop gain.