A short take-off and vertical landing aircraft is a fixed-wing aircraft that is able to take off from a short runway and land vertically. The formal NATO definition is:
A Short Take-Off and Vertical Landing aircraft is a fixed-wing aircraft capable of clearing a 15 m obstacle within 450 m of commencing take-off run, and capable of landing vertically.
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 vertical and/or short take-off and landing (V/STOL) aircraft is an airplane able to take-off or land vertically or on short runways. Vertical takeoff and landing (VTOL) aircraft are a subset of V/STOL craft that do not require runways at all. Generally, a V/STOL aircraft needs to be able to hover. Helicopters are not considered under the V/STOL classification as the classification is only used for aeroplanes, aircraft that achieve lift (force) in forward flight by planing the air, thereby achieving speed and fuel efficiency that is typically greater than the capability of helicopters.
In aeronautics, a ducted fan is a thrust-generating mechanical fan or propeller mounted within a cylindrical duct or shroud. Other terms include ducted propeller or shrouded propeller. When used in vertical takeoff and landing (VTOL) applications it is also known as a shrouded rotor.
The General Electric TF39 is a high-bypass turbofan engine that was developed to power the Lockheed C-5 Galaxy. The TF39 was the first high-power, high-bypass jet engine developed. The TF39 was further developed into the CF6 series of engines, and formed the basis of the LM2500 and LM6000 marine and industrial gas turbine. On September 7, 2017, the last active C-5A powered with TF39 engines made its final flight to Davis-Monthan Air Force Base for retirement. The TF39 was effectively retired, and all remaining active C-5 Galaxies are Rebuilt C-5M Super Galaxies, powered by F138-GE-102 engines.
The Bell X-14 is an experimental VTOL aircraft flown in the United States in the 1950s. The main objective of the project was to demonstrate vectored thrust horizontal and vertical takeoff, hover, transition to forward flight, and vertical landing.
The Hiller X-18 was an experimental cargo transport aircraft designed to be the first testbed for tiltwing and V/STOL technology.
The Avro Canada VZ-9 Avrocar is a VTOL aircraft developed by Avro Canada as part of a secret U.S. military project carried out in the early years of the Cold War. The Avrocar intended to exploit the Coandă effect to provide lift and thrust from a single "turborotor" blowing exhaust out of the rim of the disk-shaped aircraft. In the air, it would have resembled a flying saucer.
The Lockheed XV-4 Hummingbird was a U.S. Army project to demonstrate the feasibility of using VTOL for a surveillance aircraft carrying target-acquisition and sensory equipment. It was designed and built by the Lockheed Corporation in the 1960s, one of many attempts to produce a V/STOL vertical take off/landing jet. Both prototype aircraft were destroyed in accidents.
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.
The Piasecki VZ-8 Airgeep was a prototype vertical takeoff and landing (VTOL) aircraft developed by Piasecki Aircraft. The Airgeep was developed to fulfill a U.S. Army Transportation Research Command contract for a flying jeep in 1957. The flying jeep was envisioned to be smaller and easier to fly than a helicopter.
The Rolls-Royce LiftSystem, together with the F135 engine, is an aircraft propulsion system designed for use in the STOVL variant of the F-35 Lightning II. The complete system, known as the Integrated Lift Fan Propulsion System (ILFPS), was awarded the Collier Trophy in 2001.
The General Electric CF700 is an aft-fan turbofan development of the CJ610 turbojet. The fan blades are an extension of the low-pressure turbine blades.
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.
Lift fan is an aircraft configuration in which lifting fans are located in large holes in an otherwise conventional fixed wing or fuselage. It is used for V/STOL operation.
The General Electric X353-5 was an unusual, high bypass ratio, liftfan system developed for the Ryan XV-5 Vertifan V/STOL research aircraft. Two General Electric J85-5 turbojets were used for propulsion in wing-borne flight. During lift, the exhaust from these turbojets was diverted through ducting to a pair of vertically mounted turbine/fan units buried in the aircraft wings. These turbine/fan units were similar in concept to the aft fan units on the General Electric CJ805 -23, the main difference being that the turbine blades of the X353-5 were outboard of the fan, rather than inboard. Each engine supplied half the exhaust gas needed to drive each fan unit. A cross-over duct kept both fans turning uniformly in the event of either engine failing. The aircraft also had a smaller turbine/fan mounted in the aircraft nose, which was used to control pitch. This pitch fan was similar in design to the main fan units and utilised 10.5% of the gas generator exhaust gas flow. Beneath each fan was a series of spanwise exit louvres, ganged together, which were used to vector the fan thrust in lift mode. Effectively, the bypass ratio was 12.16:1 in lift mode.
The XTI TriFan 600 is a vertical takeoff and landing aircraft currently under development by XTI Aircraft Company. The TriFan 600 is referred to as a Vertical Lift Crossover Airplane (VLCA) by XTI to differentiate its range and speed from the many short-range, low-speed electric VTOL (eVTOL) aircraft under development.
An annular lift fan aircraft is a conceptual vertical takeoff and landing (VTOL) aircraft that was first systematically and numerically investigated in 2015. This concept was proposed to offer a VTOL solution for both high hovering efficiency and high cruise speed, using a large annular lift fan instead of the relatively small conventional circular lift fans used in the Ryan XV-5 Vertifan and the F-35B Lightning II (JSF).
