ABSTRACT
Summary A simulation in the B747-400 was conducted at NASA Ames Research Center that compared how crews handled voice and data link air trac control (ATC) messages in a single medium versus a mixed voice and data link ATC environment e interval between ATC messages was also varied to examine the
inuence of time pressure in voice, data link, and mixed ATC environments. For messages sent via voice, transaction times were lengthened in the mixed media environment for closely spaced messages. e type of environment did not aect data link times. However, messages times were lengthened in both single and mixed-modality environments under time pressure. Closely spaced messages also increased the number of requests for clarication for voice messages in the mixed environment and review menu use for data link messages. Results indicated that when time pressure is introduced, the mix of voice and data link does not necessarily capitalize on the advantages of both media. ese ndings emphasize the need to develop procedures for managing communication in mixed voice and data link environments.
