This flight validation program was conducted at the NASA Langley Research Center to perform "vortex flap" research to improve the aerodynamic performance of delta wing aircraft at high angles of attack and to verify the design tools and expected performance benefits for the vortex flap concept. The primary emphasis of the flight program was the measurement of pressure profiles along the vortex flap and wing to provide verification of design techniques. Subject of a large NASA and industry effort, the investigation also included analytical and wind-tunnel studies. You can see the specially-designed vortex flap extension on the leading edge of the wing. The flap concept controlled the characteristics of the vertical flow shed off the leading edge of the swept delta wing during flight. Mounted on the spine of the fuselage, the backbone, is a scanning flow-visualization system [the black hump on the backbone], and the white lines on the upper surface of the right wing are pressure belts.

The flight tests established a data base on the use of a wing leading-edge vortex flap as a means to validate the design and analysis methods associated with the development of such a vortical flow-control concept. The overall experiment included: refinements of the design codes for vortex flaps; numerous wind tunnel entries to aid in verifying design codes and determining basic aerodynamic characteristics; design and fabrication of the flaps, structural modifications to the wing tip and leading edges of the test aircraft; development and installation of an aircraft research instrumentation system, including wing and flap surface pressure measurements and selected structural loads measurements; ground-based simulation to assess flying qualities; and finally, flight testing.

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Process definition
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F-106B 57-2516 [NASA NF-106B N816NA] was officially retired in 1992 and is now on static display in the Virginia Air and Space Center in Hampton, Virginia. (data source: NASA)

The papers included below include reviews of the operational aspects associated with the flight experiment, which includes a description of modifications to the research airplane, the overall flight test procedures, and problems encountered. Selected research results are also presented to illustrate the accomplishments of the research effort.

REPORTS and ARTICLES
In-Flight Flow Visualization Results of the F-106B with a Vortex Flap Results [pdf]: 2003 Report by Jay M. Brandon, James B. Hallissy, Philip W. Brown and John E. Lamar of the NASA Langley Research Center dated March 2003.

In-Flight Flow Visualization Results of the F-106B with a Vortex Flap Results Report [pdf]: 2001 Report by Jay M. Brandon, James B. Hallissy, Philip W. Brown and John E. Lamar of the NASA Langley Research Center as presented Symposium, Loen Norway, 7-11, 2001.

In 1985 NASA took F-106B 57-2507 and cut in in half lengthways in order to use the left side of the aircraft and wing in Wind Tunnel tests for the Virtex Flap In-Flight Flow Visualization project. NASA called it the F-53 Full Scale Wind Tunnel Test.

Here is a 1985 Article in the 16 Mar 1985 Flight International where NASA sawed the F-106B in-half for testing the vortex flaps on the remaining wing in the wind tunnel. [Flightglobal archives]

Article in the 17 Sep 1988 Flight International [from the Flightglobal archives]

NASA NasaCRgis: NF-106B N816NA Gallery