Crew communication as a factor in aviation accidents

Abstract

SUMMARYA method for the detailed analysis of within-crew communications is developed and applied in formulating and testing several hypotheses about the basic structure of the aircrew communication process. Planning and explanation are shown to be well-structured discourse types, described by formal rules. These formal rules are integrated with those describing the other most important discourse type within the cockpit: the command-and-control speech act chain. Command-and-control discourse is described as a sequence of speech acts for making requests (including orders and suggestions), for making reports, for supporting or challenging statements, and for acknowledging previous speech acts. Mitigation level, a linguistic indication of indirectness and tentativeness in speech, was an important variable in several hypotheses. Testing these hypotheses showed that the speech of subordinates is more mitigated than the speech of superiors, that the speech of all crewmembers is less mitigated when they know that they are in either a problem or emergency situation, and that mitigation is a factor in failures of crewmembers to initiate discussion of new topics or have suggestions ratified by the captain. The test results also indicated that planning and explanation are more frequently performed by captains than by other crewmembers, are done more during crew-recognized problems, and are done less during crew-recognized emergencies.

Nonroutine transactions in controller‐pilot communication

“…Speech Acts and Topics. Using a set of speech acts adapted from prior aviation research (e.g., Goguen, Linde, & Murphy, 1986), each unit was coded for speech act category. For example, the first controller turn in Table 1 contained a callsign identification and four commands.…”

“Anybody on this list that you're more worried about?” Qualitative analysis exploring the functions of questions during end of shift handoffs

“…In highly constrained interactional contexts, the number of questions one asks is seen as a measure of dominance in the interaction as has been shown in multiple studies of physician–patient communication 11 12. In aviation, the directness of the question asked has been related to power, with less powerful crew members likely to use indirect communication and questions 13 14. In theory, there are no constraints on who can ask questions in casual conversation, although doing so habitually would likely be seen as being ‘pushy’ or ‘nosy’ 15.…”

Galilean satellite ephemerides E5

“…Essentially the first addition of δt removes the erroneous application of the phase effects with the incorrect sign and the second application of δt actually corrects for the phase problem. Additionally, some infra-red astrometric mutual event separations were obtained from Goguen et al (1988) in 1985 as well as in 1991 (Goguen 1994). Astrometric separations from the 1991 mutual event season which were employed in the development of E5 were also published by Mallama (1992a), Spencer (1993) and by Descamps (1994).…”

“…Recent estimates of the albedo variations by several scientists (Goguen 1994;Mallama 1993;Riedel 1994;Gaskell 1995) are not entirely consistent and for the Galileo-mission ephemerides it was decided to limit the processing to computation of the difference between center of light and center of figure due to Lambert scattering only, since it represents a reasonable first approximation to the scattering properties of the satellites if one excludes albedo variations (viz., effects which depend upon features on the satellites and which vary with planetocentric longitude of the central disc). The extrapolation of Voyager-derived scattering properties (which occurred at high phase angle) to the scattering properties of the satellites at low phase angle as observed from the Earth is not entirely satisfactory and the several efforts done to date are not entirely consistent with one another.…”

“…The E4 ephemerides employed the previously mentioned Voyager data, mutual event data from 1973 and 1979 corrected for phase effects by adding δt to the observation time (Aksnes et al 1986), photographic data and Jovian eclipse timings, as well as additional mutual event astrometric measurements from 1985 and 1991 (Aksnes et al 1986;Franklin et al 1991;Kaas et al 1997;Descamps 1994;Goguen et al 1988;Goguen 1994;Mallama 1992), and additional photographic observations from Pascu (1993) covering the interval 1980-1991. Threeyears' of CCD data from Flagstaff (Monet et al 1994;Owen 1995) were evaluated, but not employed in developing the E4 ephemerides.…”