The Airborne Polar Experiment (APE), part-funded by the European Community's specific RTD programme in the field of Environment and Climate, has successfully completed a series of stratospheric measurements of ozone destruction in the Arctic using a converted Russian spy plane. The recent mission, which ran from 20 December 1996 until 15 January 1997, was run in conjunction with POLECAT, funded by the German Ozone Research Programme. The major goal of the mission was to prove the concept of stratospheric measurements onboard the Russian plane "Geophysika". This has been completely successful, and yielded several interesting preliminary results, including a previously unknown type of polar stratospheric cloud and an unexpectedly low number of aerosol droplets. Polar stratospheric clouds are responsible for the release of ozone-destroying chlorine species which derive mainly from man-made compounds. Essential aspects of the behaviour and characteristics of these clouds are still very uncertain. The APE mission is the first to use a manned aeroplane to monitor these clouds. Previous experiments in the Arctic region have had to rely on the chance that unmanned balloons will pass by these clouds. The APE mission has proved the viability of further missions. The Airborne Polar Experiment, which is also funded by the Italian National Programme for Antarctic Research and the European Science Foundation, is part of the overall European stratospheric ozone research strategy. This started with the EASOE (1991-1992) and SESAME (1994-1995) campaigns in polar and mid-latitudes, and will be continued by the THESEO campaign which will extend research into tropical areas during 1998 and 1999.