Tiltrotor combines helicopter VTOL with fixed-wing speed and range. Generates lift and propulsion using rotors mounted on fixed wing shafts. Rotors tilt horizontally for vertical flight, then forward for speed
Angle of attack is the angle between a body's reference line and fluid motion. Wing chord line or fuselage horizontal line serves as reference. Some authors use zero lift axis instead of arbitrary chord line
Matthew Piers Watt Boulton patented aileron control system in 1868. Wright brothers and Glenn Curtiss fought patent battle over lateral control. Ailerons first appeared in print in 1908, replacing wing warping. Robert Esnault-Pelterie's glider in 1904 pioneered modern aileron use
Transponder is an electronic device that responds to radio-frequency interrogations. Aircraft use transponders for identification on air traffic control radar. Transponders operate on 1030 MHz for interrogation and 1090 MHz for replies
APUs provide energy for non-propulsion functions on vehicles. Common on large aircraft, naval ships, and some land vehicles. Produce 115V AC or 28V DC voltage for aircraft systems
Wingtip devices reduce drag and improve aircraft efficiency. They increase lift-to-drag ratio without significantly increasing wingspan. Winglets prevent wingtip vortices and improve aircraft handling. They reduce wake vortices and improve safety for following aircraft