Language is the most efficient method of human communication. We all learned a language in the first four to five years of our lives, and we practiced it for hours and years on end every day, and, so, became highly trained experts in language use. Verbal communication is fast compared to the Morse code, simple in terms of additional technical equipment, extremely adaptable to different kinds of channels, media, and situational conditions. Language processing is sturdy and secure; there is, on average, one error per thousand executions of a production procedure. The investigation of communication under conditions of high risk, time pressure, and task load is systematically located at the intersection of three fields of research: the social-psychological investigation of communicative interaction, the psycholinguistics of language production and understanding, and the cognitive psychology of dual task performance. In this talk, the focus will be laid on social psychological issues of communicative interactions, i.e. on linguistically evident features of team members' behaviour under conditions of increasing task load. Linguistic performance under varying degrees of stress will be described in order to find out whether linguistic patterns change in relation to the amount of workload. The following questions will be looked into:

• How does linguistic interaction vary in relation to the level of workload? Which elements of the utterances and which mechanism of language production persist and which are eliminated under the conditions of high workload and danger?
• What do the linguistic form and the content of samples of communicative utterances under different degrees of task load tell us about the crew members' performance in non-verbal domains like situational awareness, crew resource management, emotional affectedness.