Short-duration upper atmospheric optical flahses were recorded on the night of 8 July, 1993 (9 July UT) from the NASA DC-8 Airborne Laboratory flying over the American Midwest. All-sky video images from an intensified silicon intensified target (ISIT) camera revealed 19 upper atmospheric flashes occurring over a period of ~100 min. The flashes were similar in appearance to previously reported ground and shuttle-based video observations. Detailed analysis of 12 of the events yielded these parameters: (1) duration ≤17 ms; (2) brightness 10--50 kR, roughly that of bright aurorae; (3) terminal heights 30--100 km, with a mean of ~60 km; (4) horizontal extent 10--50 km; (5) emission volume >1000 km3. The relative frequency of the optical flashes was (6) 1:200-1:400 compared to negative cloud-to-ground discharges and 1:20-1:40 compared to positive cloud-to-ground discharges. ¿ American Geophysical Union 1993