The F-18 HARV retains the basic F-18 cockpit controls with some exceptions. The pilot's center control stick is relatively typical of a modern fighter aircraft. The F-18 HARV has no weapons delivery capability. Independent throttling of the left or right engine is possible through split throttle levers located on the left console. The pilot's friction control is provided for adjustment of throttle lever force. The three-position (extend, hold, and retract) speed brake thumb switch is located on the inboard side of the right-engine throttle lever. The primary cockpit displays include a left- and right-side cathode-ray tube display, referred to as the DDIs, and the heads-up display (HUD). The DDIs and HUD are generally used to display primary flight condition information such as airspeed, altitude, altitude rate, attitude, heading, RFCS status, etc. Other flight conditions displayed include angle of attack (AOA), Mach number, and load factor. The HUD also provides primary flight condition information to the pilot without having to refer to the DDIs. Select flight controls information also can be presented on the HUD. The twenty pushbuttons located on the periphery of each DDI are used to select a variety of displays for pilot interrogation of F-18 HARV systems. These displays are pilot selectable and menu driven. Various aerodynamic research experiments were conducted on the F-18 HARV. Switches for control of these experiments were located on the research systems control panel located at the lower center of the instrument panel. These switches operated in conjunction with the gun trigger switch. The configuration of this panel and the function of the gun trigger switch varied with the particular experiment flown.