Method used by an aircraft to depart and return to the ground
Aircraft
have different ways to
take off and land
. Conventional
airplanes
accelerate along the ground until reaching a speed that is sufficient for the airplane to
takeoff
and climb at a safe speed. Some airplanes can take off at low speed, this being a short takeoff. Some aircraft such as helicopters and
Harrier jump jets
can
take off and land vertically
. Rockets also usually take off vertically, but some designs can land horizontally.
Horizontal takeoff and landing
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Aircraft
[
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]
Conventional takeoff and landing (CTOL)
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Takeoff
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Takeoff
is the phase of
flight
in which an
aircraft
goes through a transition from moving along the ground (
taxiing
) to flying in the air, usually starting on a
runway
. For
balloons
,
helicopters
and some specialized fixed-wing aircraft (
VTOL
aircraft such as the
Harrier
), no runway is needed. Takeoff is the opposite of
landing
.
Landing
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]
Landing
is the last part of a
flight
, where a flying
aircraft
or
spacecraft
(or
animals
) returns to the ground. When the flying object returns to water, the process is called
alighting
, although it is commonly called "landing" and "touchdown" as well. A normal aircraft flight would include several parts of flight including
taxi
,
takeoff
,
climb
,
cruise
,
descent
and landing.
Reduced takeoff and landing (RTOL)
[
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]
RTOL
aircraft require shorter runways than conventional types, typically 3,500 feet (1,100 m) to 4,500 feet (1,400 m).
[1]
[2]
Short takeoff and landing (STOL)
[
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]
STOL
is an
acronym
for
short take-off and landing
,
aircraft
with very short
runway
requirements, typically between 2,000 feet (610 m) to 3,500 feet (1,100 m).
[2]
Catapult launch and arrested recovery (CATOBAR)
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]
CATOBAR (catapult assisted takeoff but arrested recovery) is a system used for the launch and recovery of aircraft from the deck of an
aircraft carrier
. Under this technique, aircraft are launched using a
catapult
and land on the ship (the recovery phase) using
arrestor wires
.
Although this system is more costly than alternative methods, it provides greater flexibility in carrier operations, since it allows the vessel to support conventional aircraft. Alternate methods of launch and recovery can only use aircraft with
STOVL
or
STOBAR
capability.
Short Take Off But Arrested Recovery (STOBAR)
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]
STOBAR
(Short Take Off But Arrested Recovery) is a system used for the launch and recovery of aircraft from the deck of an
aircraft carrier
, combining elements of both
STOVL
(Short Take-Off and Vertical Landing) and
CATOBAR
(Catapult Assisted Take-Off But Arrested Recovery).
Spacecraft (HTHL)
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]
Horizontal takeoff, horizontal landing
(
HTHL
) ? is the mode of operation for the first private commercial spaceplane, the two-stage-to-space
Scaled Composites Tier One
from the
Ansari X-Prize
SpaceShipOne
/
WhiteKnightOne
combination. It is also used for the upcoming
Tier 1b
SpaceShipTwo
/
WhiteKnightTwo
combination. A prominent example of its use was the
North American X-15
program. In these examples the space craft are carried to altitude on a "mother ship" before launch.
The failed proposals for NASA Space Shuttle replacements,
Rockwell X-30
NASP used this mode of operation but were conceived as single stage to orbit.
The
Lynx rocketplane
was a
suborbital
HTHL spaceplane developed by
XCOR Aerospace
that was slated to begin atmospheric flight testing in late 2011.
[3]
However, after numerous delays, XCOR Aerospace went bankrupt in 2017 without finishing a prototype.
[4]
Reaction Engines Skylon
, a design descendant of the 1980s British
HOTOL
("Horizontal Take-Off and Landing") design project, is an HTHL
spaceplane
currently in the early stages of development in the
United Kingdom
.
[5]
Both the
Lynx rocketplane
and
SpaceShipTwo
have been proffered to NASA to carry
suborbital
research payloads in response to NASA's suborbital reusable launch vehicle (sRLV) solicitation under the NASA Flight Operations Program.
[6]
An early example was the 1960s
Northrop HL-10
atmospheric test aircraft where the HL stands for "Horizontal Lander".
[7]
Vertical takeoff and landing
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]
Different terms are used for takeoff and landing depending on the source of thrust used. VTVL uses rockets, whereas VTOL uses air, propelled via some kind of rotor system.
Aircraft (VTOL)
[
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]
Vertical Take-Off and Landing
(
VTOL
)
aircraft
includes
fixed-wing aircraft
that can hover, take off and land vertically as well as
helicopters
and other aircraft with powered rotors, such as
tiltrotors
.
[8]
[9]
[10]
[11]
The terminology for spacecraft and rockets is
VTVL
(vertical takeoff with vertical landing).
[12]
Some VTOL aircraft can operate in other modes as well, such as
CTOL
(conventional take-off and landing),
STOL
(short take-off and landing), and/or
STOVL
(short take-off and vertical landing). Others, such as some helicopters, can only operate by VTOL, due to the aircraft lacking
landing gear
that can handle horizontal motion. VTOL is a subset of
V/STOL
(vertical and/or short take-off and landing).
Besides the ubiquitous helicopter, there are currently two types of VTOL aircraft in military service: craft using a
tiltrotor
, such as the
Bell
Boeing
V-22 Osprey
, and aircraft using directed jet thrust such as the
Harrier family
. In the civilian sector currently only helicopters are in general use (some other types of commercial VTOL aircraft have been proposed and are under development as of 2017).
Rocket (VTVL)
[
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]
Vertical takeoff, vertical landing
(
VTVL
) is a form of takeoff and landing for rockets. Multiple VTVL craft have flown. The most widely known and commercially successful VTVL rocket is SpaceX's
Falcon 9
first stage.
VTVL technologies were developed substantially with small rockets after 2000, in part due to
incentive prize competitions
like the
Lunar Lander Challenge
. Successful small VTVL rockets were developed by
Masten Space Systems
,
Armadillo Aerospace
, and others.
Vertical takeoff and horizontal landing
[
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]
Aircraft (VTOHL)
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]
In aviation the term VTOHL ("Vertical Take-Off and Horizontal Landing") as well as several VTOHL aviation-specific subtypes: VTOCL, VTOSL, VTOBAR exist.
Zero length launch system
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]
The
zero length launch system
or
zero length take-off system
(ZLL, ZLTO, ZEL, ZELL) was a system whereby
jet
fighters
and
attack aircraft
were intended to be placed upon
rockets
attached to mobile
launch platforms
. Most zero length launch experiments took place in the 1950s, during the
Cold War
.
Spacecraft (VTHL)
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]
Vertical takeoff, horizontal landing
(
VTHL
) is the mode of operation for all current and formerly operational orbital
spaceplanes
, such as the
Boeing X-37
, the
NASA
Space Shuttle
, the 1988 Soviet
Buran space shuttle
, and the
PRC
CSSHQ
/
Shenlong
. For launch vehicles an advantage of VTHL over HTHL is that the wing can be smaller, since it only has to carry the landing weight of the vehicle, rather than the takeoff weight.
[13]
There have been several VTHL proposals that never flew, including the circa-1960
USAF
Boeing X-20 Dyna-Soar
project, NASA Space Shuttle proposed replacements,
Lockheed Martin X-33
, and
VentureStar
. The 1990s NASA concept spaceplane, the
HL-20 Personnel Launch System
(HL stands for "Horizontal Lander"), was VTHL, as was a circa-2003 derivative of the HL-20, the
Orbital Space Plane
concept.
As of March 2011
[update]
, two VTHL
commercial
spaceplanes were in various stages of proposal/development, both successors to the HL-20 design. The
Sierra Nevada Corporation
Dream Chaser
follows the
outer mold line
of the earlier HL-20.
The circa-2011 proposed
Orbital Sciences Corporation
Prometheus
was a
blended lifting body
spaceplane that followed the outer mold line of the circa-2003 Orbital Space Plane, itself a derivative of the HL-20; however, Prometheus did not receive any NASA contracts and Orbital has announced they will not pursue further development.
[14]
German Aerospace Center
studied reusable VTHL
Liquid Fly-back Boosters
from 1999. Design was intended to replace
Ariane 5
solid rocket boosters
.
[15]
The
U.S. government
-funded,
US$
250,000,000,
Reusable Booster System
program, initiated by the USAF in 2010,
[16]
had specified a high-level requirement that the design be VTHL,
[17]
but the funding was discontinued after 2012.
[18]
In 2017 DARPA selected a VTHL design for
XS-1
.
Horizontal takeoff and vertical landing
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]
Few airplanes can operate with conventional takeoff and vertical landing (and its subtypes
STOVL
, CATOVL) as the
F-35B
.
Horizontal takeoff and vertical landing
(
HTVL
) in spaceflight has not been used, but has been proposed for some systems that use a two-stage to orbit launch system with a plane based first stage, and a capsule return vehicle. One of the few HTVL concept vehicles is the 1960s concept spacecraft
Hyperion SSTO
, designed by
Philip Bono
.
[19]
Multi-mode configurations
[
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]
Vehicles use more than one mode also exist.
Vertical/Short takeoff landing (V/STOL)
[
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]
Vertical and/or short take-off and landing
(V/STOL)
aircraft
that are able to take off or land vertically or on short runways. Vertical takeoff and landing (
VTOL
) includes craft that do not require runways at all. Generally, a V/STOL aircraft needs to be able to hover; helicopters are not typically considered under the V/STOL classification.
A rolling takeoff, sometimes with a ramp (
ski-jump
), reduces the amount of thrust required to lift an aircraft from the ground (compared with vertical takeoff), and hence increases the payload and range that can be achieved for a given thrust. For instance, the Harrier is incapable of taking off vertically with a full weapons and fuel load. Hence V/STOL aircraft generally use a runway if it is available. I.e. Short Take-Off and Vertical Landing (
STOVL
) or Conventional Take-off and Landing (
CTOL
) operation is preferred to
VTOL
operation.
V/STOL was developed to allow fast jets to be operated from clearings in forests, from very short runways, and from small
aircraft carriers
that would previously only have been able to carry
helicopters
.
The main advantage of V/STOL aircraft is closer basing to the enemy, which reduces response time and tanker support requirements. In the case of the
Falklands War
, it also permitted high performance fighter air cover and ground attack without a large aircraft carrier equipped with a catapult.
The latest V/STOL aircraft is the
F-35B
, which entered service in 2015.
[20]
References
[
edit
]
- ^
Wragg, David W. (1973).
A Dictionary of Aviation
(first ed.). Osprey. p. 222.
ISBN
9780850451634
.
- ^
a
b
Campbell, John P. "
Overview of Powered Lift Technology
", George Washington University.
- ^
Messier, Doug (2011-02-23).
"Lynx Development Proceeds Towards First Test Flight"
. Parabolic Arc
. Retrieved
2011-02-28
.
work is coming along nicely on building the first test flight vehicle which the company hopes to fly by the end of the year.
- ^
Foust, Jeff (2017-11-15).
"XCOR Aerospace Files for Bankruptcy"
.
Space.com
. Retrieved
2019-08-28
.
- ^
"Skylon FAQ"
.
Frequently Asked Questions
. Reaction Engines Limited. 2010. Archived from
the original
on 2015-06-02
. Retrieved
2011-02-06
.
- ^
"sRLV platforms compared"
.
NASA
. 2011-03-07. Archived from
the original
on 2021-02-20
. Retrieved
2011-03-10
.
Lynx: Type: HTHL / Piloted ... SpaceShipTwo: Type: HTHL / Piloted
- ^
HL-10 Lifting Body Fact Sheet
, NASA, 2009-12-03, accessed 2011-02-16.
- ^
"Vertical Takeoff & Landing Aircraft," John P. Campbell, The MacMillan Company, New York, 1962.
- ^
Rogers 1989.
- ^
Laskowitz, I.B. "Vertical Take-Off and Landing (VTOL) Aircraft."
Annals of the New York Academy of Sciences,
Vol. 107, Art.1, 25 March 1963.
- ^
"Straight Up - A History of Vertical Flight," Steve Markman and Bill Holder, Schiffer Publishing, 2000.
- ^
"Masten Space Systems Achieves First-Ever VTVL Midair Engine Relight Milestone on Path to Space."
SpaceRef.com,
29 May 2010. Retrieved: 10 July 2011.
- ^
"AIAA 2003-09-09 Flight mechanics of manned Sub-Orbital Reusable Launch Vehicles with Recommendations for Launch and Recovery-M Sarigul-Klijn & N Sarigul-Klijn"
(PDF)
.
- ^
"Orbital may wind down its commercial crew effort"
.
NewSpace Journal
. 2011-04-22
. Retrieved
2011-04-25
.
CEO Dave Thompson said ... "I don't, at this time, anticipate that we'll continue to pursue our own project in that race. We'll watch it and if an opportunity develops we may reconsider. But at this point, I would not anticipate a lot of activity on our part in the commercial crew market."
- ^
"Liquid Fly-back Booster (LFBB)"
. DLR. Archived from
the original
on 10 June 2015
. Retrieved
9 June
2015
.
- ^
"Air Force studying reusable upper stage systems for reusable booster"
.
RLV and Space Transport News
. 2010-09-20. Archived from
the original
on 2011-07-24
. Retrieved
2011-03-24
.
- ^
Cogliano (2011-03-22).
"Air Force launches $250M reusable booster initiative"
.
Dayton Business Journal
. Retrieved
2011-03-24
.
Officials anticipate awarding up to three contracts for the project, where winners would compete for individual tasks of experiments and demonstrations that address technology, processes and other attributes of a reusable booster system, or RBS. Air Force officials envision an RBS that includes a reusable rocket and an expendable upper stage rocket. The reusable rocket would be launched vertically and return, landing aircraft style on a runway, after carrying the space craft to a point where the expendable rocket could take over.
- ^
Ferster, Warren (2012-10-19).
"Prototype Reusable Rocket Effort Felled by U.S. Budget Woes"
.
Space News
. Retrieved
2012-10-21
.
- ^
Wade, Mark.
"Hyperion SSTO"
. Astronautix. Archived from
the original
on August 27, 2002
. Retrieved
2011-02-06
.
The 'Hyperion' vehicle was truly remarkable since it would have been launched horizontally and landed vertically (HTVL) ? an extremely rare combination. The payload capability was 110 passengers or 18t of cargo.
- ^
"U.S. Marines Corps declares the F-35B operational"
. United States Marine Corps. 2015-07-31
. Retrieved
2019-08-28
.
External links
[
edit
]
- The dictionary definition of
HTHL
at Wiktionary
- The dictionary definition of
VTHL
at Wiktionary
- The dictionary definition of
HTVL
at Wiktionary
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