Box model sensitivity-uncertainty calculations for O3 depletion from supersonic aircraft emissions were performed at the most perturbed locale using localized outputs of the LLNL 2-D diurnally averaged assessment model. Processes controlling N2O5, catalytic O3 loss steps O+NO2 and HO2+O3. HOx sink reactions OH+HNO3/HNO4, and the O+O2 recombination that forms O3 are identified as the dominant photochemical uncertainty sources. Guided by local sensitivities, 2-D model runs were repeated with 9 targeted input parameters altered to 1/3 of their 1-&sgr; uncertainties to put error-bounds on the predicted O3 change. Results indicate these kinetic errors can cause the predicted local O3 loss of 1.5% to be uncertain by up to 3% in regions of large aircraft NOx injection. ¿ 1997 American Geophysical Union