Describes an ASHRAE research project to develop methods to measure indoor air quality (IAQ) and comfort in aeroplanes. Notes that, although limited, the preliminary data doesn't show a specific problem or pollutant in excessive amounts. It also indicates that the flying public and flight attendants perceive the air to be of adequate quality in terms of temperature, odour and air movement. Points out that the two groups differ on humidity. Half of the flight attendants surveyed found humidity levels to be very poor to poor, but only 5.6% of the surveyed passengers agreed. The flight attendants were also more likely to relate certain symptoms to flying, the most frequent being dry and stuffy nose and stomach discomfort. Presents responses to comfort questionnaires in tables and notes the need for additional research.