A vertical take-off and landing (VTOL) aircraft is one that can take off and land vertically without relying on a runway. This classification can include a variety of types of aircraft including helicopters as well as thrust-vectoring fixed-wing aircraft and other hybrid aircraft with powered rotors such as cyclogyros/cyclocopters and gyrodynes.
A tiltrotor is an aircraft that generates lift and propulsion by way of one or more powered rotors mounted on rotating shafts or nacelles usually at the ends of a fixed wing. Almost all tiltrotors use a transverse rotor design, with a few exceptions that use other multirotor layouts.
The Bell XV-15 is an American tiltrotor VTOL aircraft. It was the second successful experimental tiltrotor aircraft and the first to demonstrate the concept's high speed performance relative to conventional helicopters.
A tiltwing aircraft features a wing that is horizontal for conventional forward flight and rotates up for vertical takeoff and landing. It is similar to the tiltrotor design where only the propeller and engine rotate. Tiltwing aircraft are typically fully capable of VTOL operations.
The Piasecki X-49 "SpeedHawk" is an American four-bladed, twin-engined experimental high-speed compound helicopter developed by Piasecki Aircraft. The X-49A is based on the airframe of a Sikorsky YSH-60F Seahawk, but utilizes Piasecki's proprietary vectored thrust ducted propeller (VTDP) design and includes the addition of lifting wings. The concept of the experimental program was to apply the VTDP technology to a production military helicopter to determine any benefit gained through increases in performance or useful load.
The Boeing X-50A Dragonfly, formerly known as the Canard Rotor/Wing Demonstrator, was a VTOL rotor wing experimental unmanned aerial vehicle that was developed by Boeing and DARPA to demonstrate the principle that a helicopter's rotor could be stopped in flight and act as a fixed wing, enabling it to transition between fixed-wing and rotary-wing flight.
The Boeing A160 Hummingbird is an unmanned aerial vehicle (UAV) helicopter. Its design incorporates many new technologies never before used in helicopters, allowing for greater endurance and altitude than any helicopter currently in operation.
A convertiplane is defined by the Fédération Aéronautique Internationale as an aircraft which uses rotor power for vertical takeoff and landing (VTOL) and converts to fixed-wing lift in normal flight. In the US it is further classified as a sub-type of powered lift. In popular usage it sometimes includes any aircraft that converts in flight to change its method of obtaining lift.
The Sikorsky S-72 was an experimental Sikorsky Aircraft compound helicopter developed as the Rotor Systems Research Aircraft (RSRA) for the National Aeronautics and Space Administration (NASA) and the United States Army. The RSRA was a testbed for rotor and propulsion systems for high-speed.
The Sikorsky X2 is an experimental high-speed compound helicopter with coaxial rotors, developed by Sikorsky Aircraft, that made its first flight in 2008 and was officially retired in 2011.
A powered lift aircraft takes off and lands vertically under engine power but uses a fixed wing for horizontal flight. Like helicopters, these aircraft do not need a long runway to take off and land, but they have a speed and performance similar to standard fixed-wing aircraft in combat or other situations.
Aurora Flight Sciences (AFS) is an American aviation and aeronautics research subsidiary of Boeing that specializes in special-purpose unmanned aerial vehicles. Aurora's headquarters is at Manassas Regional Airport.
The Aerial Reconfigurable Embedded System (ARES) was a concept for an unmanned VTOL flight module that can transport various payloads. The concept started as the TX (Transformer) in 2009 for a terrain-independent transportation system centered on a ground vehicle that could be configured into a VTOL air vehicle and carry four troops. ARES' primary function was the same as TX, to use flight to avoid ground-based transportation threats like ambushes and IEDs for units that don't have helicopters for those missions. It was to be powered by twin tilting ducted fans and have its own power system, fuel, digital flight controls, and remote command-and-control interfaces. The flight module would have different detachable mission modules for specific purposes including cargo delivery, CASEVAC, and ISR. Up to 3,000 lb (1,400 kg) of payload would be carried by a module.
The Sikorsky S-97 Raider is a high-speed scout and attack compound helicopter based on the Advancing Blade Concept (ABC) with a coaxial rotor system under development by Sikorsky Aircraft. Sikorsky planned to offer it for the United States Army's Armed Aerial Scout program, along with other possible uses. The S-97 made its maiden flight on 22 May 2015.
Future Vertical Lift (FVL) is a plan to develop a family of military helicopters for the United States Armed Forces. Five different sizes of aircraft are to be developed, sharing common hardware such as sensors, avionics, engines, and countermeasures. The U.S. Army has been considering the program since 2004. FVL is meant to develop replacements for the Army's UH-60 Black Hawk, AH-64 Apache, CH-47 Chinook, and OH-58 Kiowa helicopters. The precursor for FVL is the Joint Multi-Role (JMR) helicopter program.
The Bell V-280 Valor is a tiltrotor aircraft being developed by Bell Helicopter for the United States Army's Future Vertical Lift (FVL) program. The aircraft was officially unveiled at the 2013 Army Aviation Association of America's (AAAA) Annual Professional Forum and Exposition in Fort Worth, Texas. The V-280 made its first flight on 18 December 2017 in Amarillo, Texas.
The Sikorsky–Boeing SB-1 Defiant was the Sikorsky Aircraft and Boeing entry for the United States Army's Future Long-Range Assault Aircraft program to replace the Sikorsky UH-60 Black Hawk. It is a compound helicopter with rigid coaxial rotors, powered by two Honeywell T55 turboshaft engines; it first flew on 21 March 2019.
The Aurora XV-24 LightningStrike is an experimental unmanned aerial vehicle created by Aurora Flight Sciences and partners Rolls-Royce and Honeywell. It was developed for the Vertical Take-Off and Landing Experimental Aircraft program.
