A series of test have been conducted in the Langley 30-by-60 Foot Tunnel to determine the effectiveness of several forebody control devices on a 10-percent-scale model of the F-15E. These test are part of a cooperative research program with the U.S. Air Force Wright Laboratory and the McDonnell Aircraft Company to determine the suitability of applying forebody controls to the F-15E aircraft. The forebody controls under investigation included mechanical concepts, such as deflectable strakes and rotating-randome devices, and pneumatic concepts, such as slotted-nozzle blowing. All these concepts are designed to provide increased maneuverability by enhancing yaw control at high angles of attack where conventional rudders become ineffective. Results from the tests show that the F-15E is well suited for the application of forebody-controls technology. After conducting a number of parametric variations, several mechanical and pneumatic forebody control options were identified that were capable of providing high levels of yaw control while minimizing the impact on other aircraft systems. Other desirable characteristics exhibited by these concepts were that the control effectiveness was retained over wide ranges of sideslip and that the level of yawing moment was easily controlled by varying either the mechanical deflection or the blowing rate. Subsequent piloted simulation studies conducted by the McDonnell Aircraft Company have shown that these improved levels of yaw control would significantly enhance the maneuverability of the aircraft. The promising results that were obtained during these tests have spawned interest in a flight-test program and possible future application to the F-15E aircraft.
