CTOL in the context of "Aircraft flight control system"

An aircraft catapult is an acceleration device used to help fixed-wing aircraft reach liftoff speed (V_LOF) faster during takeoff, typically when trying to take off from a very short runway, as otherwise the aircraft engines alone cannot get the aircraft to sufficient airspeed quickly enough for the wings to generate the lift needed to sustain flight. Launching via catapults enables aircraft that typically are only capable of conventional takeoffs, especially heavier aircraft with significant payloads, to perform short takeoffs from the roll distances of light aircraft. Catapults are usually used on the deck of a ship — such as the flight deck of an aircraft carrier — as a form of assisted takeoff for navalised aircraft, but can also be installed on land-based runways, although this is rare.

Historically it was most common for seaplanes (which have pontoons instead of wheeled landing gears and thus cannot utilize runways) to be catapulted from ships onto nearby water for takeoff, allowing them to conduct aerial reconnaissance missions and be crane-hoisted back on board during retrieval, although by the late First World War their roles are largely supplanted by the more versatile biplanes that can take off and land on carrier decks unassisted. During the Second World War before the advent of escort carriers, monoplane fighter aircraft (notably the Hawker Hurricane) would sometimes be catapulted from "catapult-equipped merchant" (CAM) vessels for one-way sorties to repel enemy aircraft harassing shipping lanes, forcing the returning pilot to either divert to a land-based airstrip, jump out by parachute, or ditch in the water near the convoy and wait for rescue. By the time fleet carriers became the norm in WW2, catapult launches have become largely unnecessary and carrier-based fighter-bombers would routinely perform self-powered takeoffs and landings off and onto carrier decks, especially during the naval aviation-dominated Pacific War between the United States and the Empire of Japan. However, escalating arms races during the Cold War accelerated the adoption of the heavier jet aircraft for naval operations, thus motivating the development of new catapult systems, especially after the popularization of angled flight decks further limited the practical distance available as takeoff runways. Nowadays, jet aircraft can launch from aircraft carriers via either catapults or ski-jump deck, and perform optics-assisted landing onto the same ship with help from decelerative arresting gears.

Landing gear is the undercarriage of an aircraft or spacecraft that is used for engaging the surface — typically land, but may also be the surface of a water body — when parking, taxiing, takeoff or landing. It was also formerly called alighting gear by some manufacturers, such as the Glenn L. Martin Company. For aircraft, Stinton makes the terminology distinction undercarriage (British) = landing gear (US).

For aircraft, landing gear is the foundational part of airframe that supports the craft's weight when it is not in flight, keeping the fuselage at a clearance off the ground so it can avoid sustaining frictional/collisional damages. Wheeled landing gear is the most ubiquitous, used in almost all aircraft that perform conventional and short takeoff and landing, while skids or floats are used in aircraft that can take off and land vertically or operate from snow/ice/water. Landing gears from early aircraft are usually fixed, and remain protruded under the aircraft during flight, with no or only partial fairing coverage to reduce drag; while most modern aircraft have retractable undercarriages that fold into the fuselage during flight, which maximizes aerodynamic streamlining and allows for faster airspeeds and smoother flight control.

The Lockheed Martin F-35 Lightning II is an American family of single-seat, single-engine, supersonic stealth strike fighters. A multirole combat aircraft designed for both air superiority and strike missions, it also has electronic warfare and intelligence, surveillance, and reconnaissance capabilities. Lockheed Martin is the prime F-35 contractor with principal partners Northrop Grumman and BAE Systems. The aircraft has three main variants: the conventional takeoff and landing (CTOL) F-35A, the short take-off and vertical-landing (STOVL) F-35B, and the carrier variant (CV) catapult-assisted take-off but arrested recovery (CATOBAR) F-35C.

The aircraft descends from the Lockheed Martin X-35, which in 2001 beat the Boeing X-32 to win the Joint Strike Fighter (JSF) program intended to replace the F-16 Fighting Falcon, F/A-18 Hornet, and the McDonnell Douglas AV-8B Harrier II "jump jet", among others. Its development is primarily funded by the United States, with additional funding from program partner countries from the North Atlantic Treaty Organization (NATO) and close U.S. allies, including Australia, Canada, Denmark, Italy, the Netherlands, Norway, the United Kingdom, and formerly Turkey. Several other countries have also ordered, or are considering ordering, the aircraft.

Takeoff or take-off is the phase of flight during which an aerial vehicle leaves the ground and becomes airborne. For space vehicles that launch vertically, this is known as liftoff.

For fixed-wing aircraft that take off horizontally (conventional takeoff), this usually involves an accelerating ground run (known as the roll) on a runway to build up speed so the wings can generate enough lift. For aerostats (balloons and airships), helicopters, tiltrotors (e.g. the V-22 Osprey) and thrust-vectoring STOVL fixed-wing aircraft (e.g. the Harrier jump jet and F-35B), a helipad/STOLport is sufficient and no runway is needed.

In aviation, assisted takeoff is any external system for helping aircraft (more specifically fixed-wing aircraft) to become airborne (take off) for flight, as opposed to doing so conventionally using strictly their own propulsion. The reasons assistance might be needed include: the combined weight of the aircraft and its payloads exceeding the maximum takeoff weight; insufficient engine power by design or malfunction, insufficient available runway length (such as on the flight deck of an aviation warship), or a combination of the above. Assisted takeoff is also required for gliders, which do not have any engine and thus are unable to propel themselves for takeoffs.

The Pratt & Whitney F135 is an afterburning turbofan developed for the Lockheed Martin F-35 Lightning II, a single-engine strike fighter. It has two variants; a Conventional Take-Off and Landing (CTOL) variant used in the F-35A and F-35C, and a two-cycle Short Take-Off Vertical Landing (STOVL) variant used in the F-35B that includes a forward lift fan. The first production engines were delivered in 2009.

Developed from the Pratt & Whitney F119 engine used on the F-22 Raptor, the F135 produces around 28,000 lbf (125 kN) of thrust and 43,000 lbf (191 kN) with afterburner. The F135 competed with the General Electric/Rolls-Royce F136 to power the F-35.