Improving pilot/air traffic control voice communication in general aviation

The influence of the air traffic,control (ATC) message format and message length was investigated on the ability of general aviation pilots to read back ATC instructions. While flying a simulator, 12 pilots heard altitude and radio frequency instructions spoken in grouped format ("forty-one-hundred"), and 12 heard them. sequentially ("four-thousand-one-hundred"). Only limited evidence was found that grouped message format improved pilot memory. Specifically, pilots who received altitude and radio frequency instructions in the grouped, rather than the sequential, format produced fewer requests for clarification, especially for longer messages. Pilots were also more likely to read back the grouped instructions in sequential format, suggesting that prior experience with the sequential format influenced pilot communication involving the relatively novel grouped format in this study.