Between 1986 and 1991, after completing its use in the NASA Lightning Strike Research, F-106B 57-2516, NASA NF-106B N816NA was used in In-Flight Flow Visualization research (Vortex Flaps). It was used as the test vehicle to flight test the Vortex Flap, a flight experiment to evaluate aerodynamic characteristics of a sharp, leading-edge vortex flap system by analysis of the wing surface pressure distributions and flow visualization data. At the beginning of this program F-106B 57-2507, NASA NF-106B N607NA was used as the wind tunnel test subject. In 1985 NASA cut 57-2507 right down it's middle lengthwise to create the NASA F-53 Wind Tunnel model and used that left side of the aircraft and its wing in the wind tunnel tests prior to installing the Vortex Wing mod to 57-2516. Vortex Flap Testing was conducted in the 7 X 10-Foot High Speed Tunnel.