EG-0101-01
The Republic XF-91 Thundercepter was a single-place fighter-type airplane powered by a General Electric J47-GE-17 turbojet engine. The wing had a sweep angle of 40 degrees at the 50-percent-chord line and had inverse taper and variable incidence. The root chord (airplane center line) had a dimension of 95 inches while the wing tip chord measured 154.5 inches. The wing incidence was variable in flight through a range from -2 degrees to 5.65 degrees.
The Republic XF-91 Thundercepter appears in a 1951 NACA photograph and two NACA technical reports (Research Memoranda), but not in the flight records of the NACA High-Speed Flight Research Station. Access by the NACA research staff to the XF-91 could have resulted from the proximity at the South Base (Edwards Air Force Base) of the Republic and NACA hangars over most of the time period 1946-1954. One NACA Technical Report delt with testing performed by NACA and Republic using the inflight variable wing incidence capability, while the other Report looked at wing aileron effectiveness.