Landing gear in the context of "Takeoff"

In engineering, a mechanism is a device that transforms input forces and movement into a desired set of output forces and movement. Mechanisms generally consist of moving components which may include gears and gear trains; Belts and chain drives; cams and followers; Linkages; Friction devices, such as brakes or clutches; Structural components such as a frame, fasteners, bearings, springs, or lubricants; Various machine elements, such as splines, pins, or keys.

German scientist Franz Reuleaux defines machine as "a combination of resistant bodies so arranged that by their means the mechanical forces of nature can be compelled to do work accompanied by certain determinate motion". In this context, his use of machine is generally interpreted to mean mechanism.

The Boeing B-29 Superfortress is a retired American four-engined propeller-driven heavy bomber, designed by Boeing and flown primarily by the United States during World War II and the Korean War. Named in allusion to its predecessor, the Boeing B-17 Flying Fortress, the Superfortress was designed for high-altitude strategic bombing, but also excelled in low-altitude night incendiary bombing, and in dropping naval mines to blockade Japan. Silverplate B-29s dropped the atomic bombs on Hiroshima and Nagasaki, the only aircraft ever to drop nuclear weapons in combat.

One of the largest aircraft of World War II, the B-29 was designed with state-of-the-art technology, which included a pressurized cabin, dual-wheeled tricycle landing gear, and an analog computer-controlled fire-control system that allowed one gunner and a fire-control officer to direct four remote machine gun turrets. The $3 billion cost of design and production (equivalent to $52 billion in 2024), far exceeding the $1.9 billion cost of the Manhattan Project, made the B-29 program the most expensive of the war. The B-29 remained in service in various roles throughout the 1950s, being retired in the early 1960s after 3,970 had been built. A few were also used as flying television transmitters by the Stratovision company. The Royal Air Force flew the B-29 with the service name Washington from 1950 to 1954 when the jet-powered Canberra entered service.

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.

A strut is a structural component commonly found in engineering, aeronautics, architecture and anatomy. Struts generally work by resisting longitudinal compression, but they may also serve in tension.

A stay is sometimes used as a synonym for strut, but some sources distinguish that struts are braces for holding compressive forces apart, while stays are braces for keeping stretching forces together.

The Messerschmitt Bf 109 is a monoplane fighter aircraft that was designed and initially produced by the German aircraft manufacturer Bayerische Flugzeugwerke (BFW). Together with the Focke-Wulf Fw 190, the Bf 109 formed the backbone of the Luftwaffe's fighter force during the Second World War. It was commonly called the Me 109 by Allied aircrew and some German aces/pilots, even though this was not the official model designation.

The Bf 109 was designed by Willy Messerschmitt and Robert Lusser, who worked at BFW during the early to mid-1930s. It was conceived as an interceptor. However, later models were developed to fulfill multiple tasks, serving as bomber escort, fighter-bomber, day-, night-, all-weather fighter, ground-attack aircraft, and aerial reconnaissance aircraft. It was one of the most advanced fighters when it first appeared, being furnished with an all-metal monocoque construction, a closed canopy, retractable landing gear, and powered by a liquid-cooled, inverted-V12 aero engine. First flown on 29 May 1935, the Bf 109 entered operational service during 1937; it first saw combat during the Spanish Civil War.

A carrier-based aircraft (also known as carrier-capable aircraft, carrier-borne aircraft, carrier aircraft or aeronaval aircraft) is a navalised aircraft designed for seaborne flight operations from aircraft carriers. The term is generally applied only to shipborne fixed-wing aircraft that require a runway of some sort for takeoff and landing, as VTOL aircraft such as helicopters are inherently capable of adapting to flight operations from a wide variety of ships (not just aircraft carriers) as long as the served vessel is equipped with helipads or a sufficiently spacious deck that can provide a reliable landing area, which include helicopter carriers, amphibious assault ships, aviation-capable surface combatants (cruisers, destroyers, frigates and some corvettes), container ships and even cruiseliners.

Carrier-based aircraft are designed for many purposes including aerial combat, surface attack, anti-submarine warfare (ASW), search and rescue (SAR), carrier onboard delivery (COD), weather observation, reconnaissance and airborne early warning and control (AEW&C). Such aircraft must be able to take off from the short distance available on the carrier's flight deck and be sturdy enough to withstand the abrupt forces exerted by on a pitching deck due to sea waves. Some modern carrier aircraft are designed for catapult-assisted takeoffs and thus also need to be constructed more robust airframes and landing gears that can handle sudden forward accelerations. Arrestor hook is mandatory feature for those designed for CATOBAR or STOBAR landing, while thrust vectoring or tiltrotor nacelles are commonly seen in those capable of V/STOL operations. In addition, their wings are generally larger (thus can generate more lift) than the land-launched counterparts, and are typically able to fold up or swing back for taxiing, pushback and parking in tight quarters.

A bogie (/ˈboʊɡi/ BOH-ghee) (or truck in North American English) comprises two or more wheelsets (two wheels on an axle), in a frame, attached under a vehicle by a pivot. Bogies take various forms in various modes of transport. A bogie may remain normally attached (as on many railroad cars and semi-trailers) or be quickly detachable (as for a dolly in a road train or in railway bogie exchange). It may include suspension components within it (as most rail and trucking bogies do), or be solid and in turn be suspended (as are most bogies of tracked vehicles). It may be mounted on a swivel, as traditionally on a railway carriage or locomotive, additionally jointed and sprung (as in the landing gear of an airliner), or held in place by other means (centreless bogies).

Although bogie is the preferred spelling and first-listed variant in various dictionaries, bogey and bogy are also used.

The mechanical structure of an aircraft is known as the airframe. This structure is typically considered to include the fuselage, undercarriage, empennage and wings, and excludes the propulsion system.

Airframe design is a field of aerospace engineering that combines aerodynamics, materials technology and manufacturing methods with a focus on weight, strength and aerodynamic drag, as well as reliability and cost.