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

Abstract : This report is based on an analysis of over 48 hours of pilot-controller communications recorded from the ground-control frequency at twelve air traffic control towers. The analysis examined the complexity of controller instructions, that is, how many pieces of information a single controller transmission contains. It looked at how pilots respond to these instructions, and whether the type of response was affected by the complexity of the instructions. Particularly, it studied the effect of complexity of the instructions on communication problems, such as when pilots asked controllers to repeat their instructions or when they made an error in the readback. It also examined the incidence and possible causes of callsign confusions as well as of conceptuaL errors in pilot-controller communications. Lastly, it compared the incidence of communication problems with the transmission density (transmissions per minute) at a facility. It related these findings to what was observed in the en-route (Cardosi, 1993), terminal-radar (TRACON; Morrow, Lee, and Rodvold, 1993) and in the tower-local control (Cardosi, 1994) environment. In conclusion a series of recommendations is presented.