Three kinds of odorants were introduced in various proportions into a specially devised dynamic flow system suitable for organoleptic appraisal of the resulting odor mixture. The methods and equipment were developed under a United States Air Force contract in connection with the control of undesirable odors in hospital aircraft, without masking alarm or signal odors indicative of mechanical trouble or of an incipient fire on the airplane. The components of cabin air are: (1) odors of infected wounds and of body discharges, (2) odor control agents, (3) vapors and smokes from gasoline, hot lubricating oil and hydraulic fluid, burning electrical insulation, and scorching paint. These were appraised in experimental mixtures by the use of profile scoring. Plotting the results showed the effects of the control agents. The malodors were partly masked by aldehyde. Ozone cancelled the malodors but must be used with care. Smokes and other alarm odors were unaffected by the control agents.