An Analysis of Tower (Local) Controller - Pilot Voice Communications

The purposes of this analysis were to examine current pilot- controller communication practices in the terminal environment. Forty-nine hours of voice tapes from local positions in ten Air Traffic Control Towers ATCTs were examined. There were 8,444 controller-to-pilot messages e.g., clearances to takeoff or land, instructions to hold short or change radio frequencies, etc. examined in this study. The complexity of the controllers message i.e., the number of pieces of information was examined and the number of erroneous readbacks and pilot requests for repeats were analyzed as a function of message complexity. Pilot acknowledgements were also analyzed the numbers of full and partial readbacks, and acknowledgements only i.e., roger were tallied. Fewer than one percent of the messages resulted in communications errors. Among the error factors examined were complexity of the message, type of acknowledgement, use of call sign in the acknowledgement, type of information in error, and whether or not the controller responded to the readback error. Instances in which the controller contacted the aircraft with one call sign and the pilot acknowledged the transmission with another call sign were also examined. The report concludes with recommendations to further reduce the probability of communication errors. Pilot-controller communications