Ozone measurements in cabin air of Concorde

Abstract

In two flights of the Concorde used for development purposes (G-BBDG) measurements of both ozone in ambient air and ozone in the air supplied to the cabin were obtained simultaneously. The measurements show that the concentration of ozone in the air at its point of entry into the cabin did not exceed 1% of the ambient concentration during high altitude Mach 2 cruise. However, when the aircraft commenced its descent, engine air bleed temperatures fell rapidly giving a corresponding reduction in the rate of ozone destruction while the aircraft was still at high altitude. Under these transient conditions, short-term excursions of the ozone level occurred in the fresh air entering the cabin, rising to a maximum of 0.14 ppmv. The measurements suggest that in cruise, the cabin ozone level is unlikely to exceed 0.01 ppmv, but in the descent phase there may be a brief period when the level could peak at higher values.