STOVL
Encyclopedia
STOVL is an acronym for short take off and vertical landing.
This is the ability of some aircraft to take off from a short runway or take off vertically if it does not have a very heavy payload and land vertically (i.e. with no runway). The formal NATO definition (since 1991) is:
On aircraft carrier
s, non-catapult assisted fixed wing short-takeoffs are accomplished with the use of thrust vectoring
, that may also be used in conjunction with a runway "ski-jump". STOVL use tends to allow aircraft to carry a larger payload as compared to during VTOL use, while still only requiring a short runway. The most famous examples are the Hawker Siddeley Harrier and the Sea Harrier. Although technically VTOL aircraft, they are operationally STOVL aircraft due to the extra weight carried at take off for fuel and armaments. The same is true of the F-35B Lightning II, which demonstrated VTOL capability in test flights but is operationally STOVL.
tailsitter
s were both designed around the Allison YT40 turboprop
engine driving contra-rotating propellers
.
The British Hawker P.1127
took off vertically in 1960, and demonstrated conventional take off in 1961. By 1964 the first development aircraft, the Hawker Siddeley Kestrel, were flying. These were flown by a tripartite squadron of British, US and West German pilots. The first Hawker Siddeley Harrier flew in 1967.
In 1962, Lockheed built the XV-4 Hummingbird for the U.S. Army. It sought to "augment" available thrust by injecting the engine exhaust into an ejector pump in the fuselage. First flying vertically in 1963, it suffered a fatal crash in 1964. It was converted into the XV-4B Hummingbird for the U.S. Air Force as a testbed for separate, vertically mounted lift engines, similar to those used in the Yak-38 Forger
. That plane flew and later crashed in 1969. The Ryan XV-5 Vertifan, which was also built for the U.S. Army at the same time as the Hummingbird, experimented with gas driven lift fans. That plane used fans in the nose and each wing, covered by doors which resembled half garbage can lids when raised. However, it crashed twice, and proved to generate a disappointing amount of lift, and was difficult to transition to horizontal flight.
Of dozens of VTOL
and V/STOL
designs tried from the 1950s to 1980s, only the subsonic Hawker Siddeley Harrier and Yak-38 Forger
reached operational status, with the Forger being withdrawn after the fall of the Soviet Union
.
Boeing
had studied another odd-looking supersonic
fighter in the 1960s which never made it beyond photos in Aviation Week. Rockwell International
built, and then abandoned, the Rockwell XFV-12 supersonic fighter which had an unusual wing which opened up like window blind
s to create an ejector pump for vertical flight. It never generated enough lift to get off the ground despite developing 20,000 lbf
of thrust. The French had a nominally Mach 2 Dassault Mirage IIIV
fitted with no less than 8 lift engines that flew (and crashed), but did not have enough space for fuel or payload for combat missions. The German EWR VJ 101
used swiveling engines mounted on the wingtips with fuselage mounted lift engines, and the VJ 101C X1 reached supersonic flight (Mach 1.08) on July 29, 1964. The supersonic Hawker Siddeley P.1154
which competed with the Mirage IIIV for NATO use was cancelled even as the aircraft were being built.
NASA
uses the abbreviation
SSTOVL for Supersonic Short Take-Off / Vertical Landing, and as of 2011, the X-35B
/F-35B are the only aircraft to conform with this combination within one flight.
The experimental Mach 1.7 Yakovlev Yak-141
did not find an operational customer, but its rotating rear nozzle technology found good use with the F-35B.
The F-35 Lightning II is expected to enter service by 2016.
Larger STOVL designs were considered, the Armstrong Whitworth AW.681
cargo aircraft was under development when cancelled in 1965. The Dornier Do 31
got as far as three experimental aircraft before cancellation in 1970.
Although mostly a VTOL design, the V-22 Osprey
has increased payload when taking off from a short runway.
This is the ability of some aircraft to take off from a short runway or take off vertically if it does not have a very heavy payload and land vertically (i.e. with no runway). The formal NATO definition (since 1991) is:
- A Short Take-Off and Vertical Landing aircraft (aéronef à décollage court et atterrissage vertical) is a fixed-wing aircraft capable of clearing a 15 m (50 ft) obstacle within 450 m (1,500 ft) of commencing take-off run, and capable of landing vertically.
On aircraft carrier
Aircraft carrier
An aircraft carrier is a warship designed with a primary mission of deploying and recovering aircraft, acting as a seagoing airbase. Aircraft carriers thus allow a naval force to project air power worldwide without having to depend on local bases for staging aircraft operations...
s, non-catapult assisted fixed wing short-takeoffs are accomplished with the use of thrust vectoring
Thrust vectoring
Thrust vectoring, also thrust vector control or TVC, is the ability of an aircraft, rocket or other vehicle to manipulate the direction of the thrust from its engine or motor in order to control the attitude or angular velocity of the vehicle....
, that may also be used in conjunction with a runway "ski-jump". STOVL use tends to allow aircraft to carry a larger payload as compared to during VTOL use, while still only requiring a short runway. The most famous examples are the Hawker Siddeley Harrier and the Sea Harrier. Although technically VTOL aircraft, they are operationally STOVL aircraft due to the extra weight carried at take off for fuel and armaments. The same is true of the F-35B Lightning II, which demonstrated VTOL capability in test flights but is operationally STOVL.
History
In 1951, the Lockheed XFV-1 and the Convair XFYConvair XFY
|-See also:-References:NotesCitationsBibliography* Allen, Francis J. "Bolt Upright: Convair's and Lockheed's VTOL fighters". Air Enthusiast Volume 127, January/February 2007, pp. 13–20. ISSN 0143-5450....
tailsitter
Tailsitter
A tailsitter is a type of VTOL aircraft that launches and lands on its tail. One of the most famous examples of this type of aircraft is the Ryan X-13 Vertijet. Among the propeller-driven versions were the Lockheed XFV, and the Convair XFY Pogo. Studies and wind tunnel models were made of a...
s were both designed around the Allison YT40 turboprop
Turboprop
A turboprop engine is a type of turbine engine which drives an aircraft propeller using a reduction gear.The gas turbine is designed specifically for this application, with almost all of its output being used to drive the propeller...
engine driving contra-rotating propellers
Contra-rotating propellers
Aircraft equipped with contra-rotating propellers, also referred to as coaxial contra-rotating propellers, apply the maximum power of usually a single piston or turboprop engine to drive two propellers in contra-rotation...
.
The British Hawker P.1127
Hawker P.1127
The Hawker P.1127 and the Hawker Siddeley Kestrel FGA.1 were the experimental and development aircraft that led to the Hawker Siddeley Harrier, the first vertical and/or short take-off and landing jet fighter-bomber...
took off vertically in 1960, and demonstrated conventional take off in 1961. By 1964 the first development aircraft, the Hawker Siddeley Kestrel, were flying. These were flown by a tripartite squadron of British, US and West German pilots. The first Hawker Siddeley Harrier flew in 1967.
In 1962, Lockheed built the XV-4 Hummingbird for the U.S. Army. It sought to "augment" available thrust by injecting the engine exhaust into an ejector pump in the fuselage. First flying vertically in 1963, it suffered a fatal crash in 1964. It was converted into the XV-4B Hummingbird for the U.S. Air Force as a testbed for separate, vertically mounted lift engines, similar to those used in the Yak-38 Forger
Yakovlev Yak-38
The Yakovlev Yak-38 was Soviet Naval Aviation's first and only operational VTOL strike fighter aircraft, in addition to being its first operational carrier-based fixed-wing aircraft...
. That plane flew and later crashed in 1969. The Ryan XV-5 Vertifan, which was also built for the U.S. Army at the same time as the Hummingbird, experimented with gas driven lift fans. That plane used fans in the nose and each wing, covered by doors which resembled half garbage can lids when raised. However, it crashed twice, and proved to generate a disappointing amount of lift, and was difficult to transition to horizontal flight.
Of dozens of VTOL
VTOL
A vertical take-off and landing aircraft is one that can hover, take off and land vertically. This classification includes fixed-wing aircraft as well as helicopters and other aircraft with powered rotors, such as cyclogyros/cyclocopters and tiltrotors...
and V/STOL
V/STOL
Vertical and/or short take-off and landing is a term used to describe aircraft that are able to take-off or land vertically or on short runways. Vertical takeoff and landing describes craft which do not require runways at all...
designs tried from the 1950s to 1980s, only the subsonic Hawker Siddeley Harrier and Yak-38 Forger
Yakovlev Yak-38
The Yakovlev Yak-38 was Soviet Naval Aviation's first and only operational VTOL strike fighter aircraft, in addition to being its first operational carrier-based fixed-wing aircraft...
reached operational status, with the Forger being withdrawn after the fall of the Soviet Union
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....
.
Boeing
Boeing
The Boeing Company is an American multinational aerospace and defense corporation, founded in 1916 by William E. Boeing in Seattle, Washington. Boeing has expanded over the years, merging with McDonnell Douglas in 1997. Boeing Corporate headquarters has been in Chicago, Illinois since 2001...
had studied another odd-looking supersonic
Supersonic
Supersonic speed is a rate of travel of an object that exceeds the speed of sound . For objects traveling in dry air of a temperature of 20 °C this speed is approximately 343 m/s, 1,125 ft/s, 768 mph or 1,235 km/h. Speeds greater than five times the speed of sound are often...
fighter in the 1960s which never made it beyond photos in Aviation Week. Rockwell International
Rockwell International
Rockwell International was a major American manufacturing conglomerate in the latter half of the 20th century, involved in aircraft, the space industry, both defense-oriented and commercial electronics, automotive and truck components, printing presses, valves and meters, and industrial automation....
built, and then abandoned, the Rockwell XFV-12 supersonic fighter which had an unusual wing which opened up like window blind
Window blind
A window blind is a type of window coverings. There are many different kinds of window blinds, using different systems and materials. A typical window blind is made with slats of fabric, wood, plastic or metal that adjust by rotating from an open position to a closed position by allowing slats to...
s to create an ejector pump for vertical flight. It never generated enough lift to get off the ground despite developing 20,000 lbf
Pound-force
The pound force is a unit of force in some systems of measurement including English engineering units and British gravitational units.- Definitions :...
of thrust. The French had a nominally Mach 2 Dassault Mirage IIIV
Dassault Mirage IIIV
|-See also:-Bibliography:* Breffort, Dominique and Andre Jouineau. "The Mirage III, 5, 50 and derivatives from 1955 to 2000." Planes and Pilots 6. Paris: Histoire et Collections, 2004. ISBN 2-913903-92-4....
fitted with no less than 8 lift engines that flew (and crashed), but did not have enough space for fuel or payload for combat missions. The German EWR VJ 101
EWR VJ 101
-See also:-Bibliography:* Rogers, Mike. VTOL: Military Research Aircraft. New York: Orion Books, 1989. ISBN 0-517-57684-8.* Winchester, Jim. "EWR-Sud VJ 101C ". X-Planes and Prototypes. London: Amber Books Ltd., 2005. ISBN 1-904687-40-7....
used swiveling engines mounted on the wingtips with fuselage mounted lift engines, and the VJ 101C X1 reached supersonic flight (Mach 1.08) on July 29, 1964. The supersonic Hawker Siddeley P.1154
Hawker Siddeley P.1154
The Hawker Siddeley P.1154 was a planned supersonic vertical/short take-off and landing fighter aircraft designed by Hawker Siddeley Aviation . Developed alongside the subsonic and smaller Hawker Siddeley P.1127/Kestrel, the P.1154 was derived from the P.1150. The P.1150 proposal did not meet NATO...
which competed with the Mirage IIIV for NATO use was cancelled even as the aircraft were being built.
NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
uses the abbreviation
Abbreviation
An abbreviation is a shortened form of a word or phrase. Usually, but not always, it consists of a letter or group of letters taken from the word or phrase...
SSTOVL for Supersonic Short Take-Off / Vertical Landing, and as of 2011, the X-35B
Lockheed Martin X-35
The Lockheed Martin X-35 was an experimental aircraft developed by Lockheed Martin for the Joint Strike Fighter Program. It was declared the winner over the Boeing X-32 and went on to enter production in the early 21st century as the F-35 Lightning II....
/F-35B are the only aircraft to conform with this combination within one flight.
The experimental Mach 1.7 Yakovlev Yak-141
Yakovlev Yak-141
The Yakovlev Yak-141 , also known as the Yak-41, is a supersonic vertical takeoff/landing fighter aircraft designed by Yakolev. It did not enter production.-Design and development:...
did not find an operational customer, but its rotating rear nozzle technology found good use with the F-35B.
The F-35 Lightning II is expected to enter service by 2016.
Larger STOVL designs were considered, the Armstrong Whitworth AW.681
Armstrong Whitworth AW.681
|-See also:-External links:*...
cargo aircraft was under development when cancelled in 1965. The Dornier Do 31
Dornier Do 31
-See also:-Bibliography:*Green, William. The Observer's Book of Aircraft. London. Frederick Warne & Co. Ltd., 1968.*Jackson, Paul A. German Military Aviation 1956–1976. Hinckley, Leicestershire, UK: Midland Counties Publications, 1976. ISBN 0-904597-03-2.-External links:**...
got as far as three experimental aircraft before cancellation in 1970.
Although mostly a VTOL design, the V-22 Osprey
V-22 Osprey
The Bell Boeing V-22 Osprey is an American multi-mission, military, tiltrotor aircraft with both a vertical takeoff and landing , and short takeoff and landing capability...
has increased payload when taking off from a short runway.