The airborne fastresponse ozone instrument was developed for use onboard the new NSF/NCAR Gulfstream V Highperformance Instrumented Airborne Platform for Environmental Research (HIAPER) research aircraft. HIAPER, with a roughly 15 km operational ceiling and a nominal air speed of 200 m/s, provides a new tool for characterization of a large and in some cases an under sampled region of the upper troposphere and lower stratosphere (UT/LS). The new instrument is designed to meet the needs of the atmospheric science community to investigate two-way stratosphere/troposphere exchange, gravity wave or other tropopause perturbations, and turbulence over a range of smaller scales perhaps induced by deep convection{Lane, 2003 #46; Pavelin, 2002 #47}.