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Point take off and landing (PTOL) is an evolving term describing special take-off and landing capabilities of unmanned aerial vehicles (UAVs) and other aircraft.
PTOL indicates that there is no requirement for a runway for operations. Instead, ‘point’ suggests that the length of runway required is near zero, implying a minimal-sized location for touchdown and takeoff. Sometimes no prepared surface at all is needed.[ citation needed ]
PTOL is assisted in certain cases by means which are not needed by vertical take-off and landing (VTOL) or by short take-off and landing (STOL) vehicles. These may include a very long cable enforcing the convergence of the aircraft from afar onto the intended touchdown point. [1] This may still be worthwhile due to maintaining the air-vehicle's advantages which are maximal simplicity leading to better cruise performance, as is the case using a fixed-wing UAV platform.
PTOL capability enables UAVs and aircraft to land and take off in very confined locations like rooftops, ship decks and forest clearings. This is comparable to VTOL, but it helps fixed-wing/simple UAVs achieve this, avoiding the complexity and cost of air-vehicle construction required for VTOL which include jet-thrust-rotation engines, engine pods or rotor tilting mechanisms.
This gives higher aerodynamic efficiency and allows smaller engines and lower cost, among other advantages. Also, a true PTOL solution means exact touchdowns even in adverse conditions such as the rolling and heaving deck of a ship, strong winds on land, or nearby obstacles such as trees or rocks. The ability to land a UAV direct onto a vehicle, with cushioning, adds safety to deployed UAVs, providing touchdown with no-runway or pre-prepared area and easing a quick change of the landing-site.
The fact that PTOL capable UAVs can land unassisted on rolling ships gives them an advantage over manned helicopters.
PTOL takeoffs are quite simple. Any rocket launched from a tube, or an UAV launched by a rail-launcher or similar means, is in effect making a point takeoff.
For the landings, several ideas have been proposed. An example for sea operations is catching a UAV in a parachute in the air behind a ship, then lowering the UAV to the deck by pulling the parachute in.
Another idea is 'cable-assisted PTOL' for fixed-wing UAVs. The UAV makes a cable connection to a surface winch (on a ship or on the ground) and the winch pulls the UAV down to the intended ‘point’. This is potentially useful for land and naval usage of fixed-wing UAVs.
Patent 4,790,497 "Point-landing method for non vertical take off and landing flying objects" [2]
Patent 4,753,400 "Shipboard air vehicle retrieval apparatus" [3]
Patent 4,311,290 "Arrestment system" [4]
An aircraft carrier is a warship that serves as a seagoing airbase, equipped with a full-length flight deck and facilities for carrying, arming, deploying, and recovering aircraft. Typically, it is the capital ship of a fleet, as it allows a naval force to project air power worldwide without depending on local bases for staging aircraft operations. Carriers have evolved since their inception in the early twentieth century from wooden vessels used to deploy balloons to nuclear-powered warships that carry numerous fighters, strike aircraft, helicopters, and other types of aircraft. While heavier aircraft such as fixed-wing gunships and bombers have been launched from aircraft carriers, these aircraft have not landed on a carrier. By its diplomatic and tactical power, its mobility, its autonomy and the variety of its means, the aircraft carrier is often the centerpiece of modern combat fleets. Tactically or even strategically, it replaced the battleship in the role of flagship of a fleet. One of its great advantages is that, by sailing in international waters, it does not interfere with any territorial sovereignty and thus obviates the need for overflight authorizations from third-party countries, reduces the times and transit distances of aircraft and therefore significantly increases the time of availability on the combat zone.
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 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.
Takeoff is the phase of flight in which an aerospace vehicle leaves the ground and becomes airborne. For aircraft traveling vertically, this is known as liftoff.
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.
The Yakovlev Yak-38 was Soviet Naval Aviation's only operational VTOL strike fighter aircraft in addition to being its first operational carrier-based fixed-wing aircraft. It was developed specifically for, and served almost exclusively on, the Kiev-class aircraft carriers.
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.
A tail-sitter, or tailsitter, is a type of VTOL aircraft that takes off and lands on its tail, then tilts horizontally for forward flight.
The Convair XFY-1 Pogo was an experimental V/STOL aircraft developed during the early years of the Cold War. It was intended to be a high-performance fighter aircraft capable of operating from small warships. Lockheed and Convair were awarded contracts to build experimental VTOL fighters, with Convair producing the XFY-1, also known as the "Pogo." It was developed as an attempt to create a practical V/STOL aircraft.
A rotorcraft or rotary-wing aircraft is a heavier-than-air aircraft with rotary wings or rotor blades, which generate lift by rotating around a vertical mast. Several rotor blades mounted on a single mast are referred to as a rotor. The International Civil Aviation Organization (ICAO) defines a rotorcraft as "supported in flight by the reactions of the air on one or more rotors".
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 SkyTote is an unmanned aerial vehicle (UAV), tail-sitter Vertical Take-Off and Landing (VTOL)-fixed wing hybrid plane, which attains the advantages of both airplane designs. In order to control the vehicle when transitioning between vertical take-off to forward flight, an adaptive neural network controller was designed by Guided Systems Technologies and used on the vehicle. The vehicle was developed by AeroVironment, under a contract given by the Air Force Research Laboratory, and its primary purpose is cargo-delivery.
The UMS Skeldar V-200 is a medium-range VTOL UAV developed by the Swedish aerospace company Saab. The Skeldar can be used for surveillance, intelligence gathering, light cargo transportation, and electronic warfare.
The Israel Aerospace Industries Panther is a tilt-rotor unmanned aerial vehicle (UAV) produced by Israel Aircraft Industries in Israel.
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.
The Xplorair is a project of compact VTOL aircraft without rotating airfoil from aerospace engineer Michel Aguilar, funded by the French Armed Forces procurement agency DGA and supported by various European aeronautics firms such as Dassault Systèmes, EADS Innovation Works, MBDA, Altran Technologies, Sogeti, Turbomeca, COMAT Aerospace and the Institut Pprime. Announced in 2007, the project aimed to develop a UAV prototype scheduled for flight in 2017, followed by a single-seater personal air vehicle (PAV) whose commercialization could occur the decade after.
Urban Air Mobility (UAM) is the use of small, highly automated aircraft to carry passengers or cargo at lower altitudes in urban and suburban areas which have been developed in response to traffic congestion. It usually refers to existing and emerging technologies such as traditional helicopters, vertical-takeoff-and-landing aircraft (VTOL), electrically propelled vertical-takeoff-and-landing aircraft (eVTOL), and unmanned aerial vehicles (UAVs). These aircraft are characterized by the use of multiple electric-powered rotors or fans for lift and propulsion, along with fly-by-wire systems to control them. Inventors have explored urban air mobility concepts since the early days of powered flight. However, advances in materials, computerized flight controls, batteries and electric motors improved innovation and designs beginning in the late 2010s. Most UAM proponents envision that the aircraft will be owned and operated by professional operators, as with taxis, rather than by private individuals.
In aviation, a ski-jump is an upward-curved ramp that allows aircraft to take off from a runway that is shorter than the aircraft's required takeoff roll. By forcing the aircraft upwards, lift-off can be achieved at a lower airspeed than that required for sustained flight, while allowing the aircraft to accelerate to such speed in the air rather than on the runway. Ski-jumps are commonly used to launch airplanes from aircraft carriers that lack catapults.
An electric vertical take-off and landing (eVTOL) aircraft is a variety of VTOL aircraft that uses electric power to hover, take off, and land vertically. This technology came about thanks to major advances in electric propulsion and the emerging need for new aerial vehicles for urban air mobility that can enable greener and quieter flights. Electric and hybrid propulsion systems (EHPS) have also the potential of lowering the operating costs of aircraft.