An aircraft is a vehicle that is able to fly by gaining support from the air. It counters the force of gravity by using either static lift or the dynamic lift of an airfoil, or, in a few cases, direct downward thrust from its engines. Common examples of aircraft include airplanes, helicopters, airships, gliders, paramotors, and hot air balloons.
Unpowered aircraft can remain airborne for a significant period of time without onboard propulsion. They can be classified as gliders, lighter-than-air balloons and tethered kites. In the case of kites, lift is obtained by tethering to a fixed or moving object, perhaps another kite, to obtain a flow of wind over the lifting surfaces. In the case of balloons, lift is obtained through inherent buoyancy and the balloon may or may not be tethered. Free balloon flight has little directional control. Gliding aircraft include sailplanes, hang gliders, and paragliders that have full directional control in free flight.
A non-rigid airship, commonly called a blimp (/blɪmp/), is an airship (dirigible) without an internal structural framework or a keel. Unlike semi-rigid and rigid airships, blimps rely on the pressure of the lifting gas inside the envelope and the strength of the envelope itself to maintain their shape. Blimps are known for their use in advertising, surveillance, and as observation platforms due to their maneuverability and steady flight capabilities.
An airship, dirigible balloon or dirigible is a type of aerostat (lighter-than-air) aircraft that can navigate through the air flying under its own power. Aerostats use buoyancy from a lifting gas that is less dense than the surrounding air to achieve the lift needed to stay airborne.
An aerostat or lighter-than-air aircraft is an aircraft that relies on buoyancy to maintain flight. Aerostats include the unpowered balloons and the powered airships.
A hybrid airship is a powered aircraft that obtains some of its lift as a lighter-than-air (LTA) airship and some from aerodynamic lift as a heavier-than-air aerodyne.
An airborne wind turbine is a design concept for a wind turbine with a rotor supported in the air without a tower, thus benefiting from the higher velocity and persistence of wind at high altitudes, while avoiding the expense of tower construction, or the need for slip rings or yaw mechanism. An electrical generator may be on the ground or airborne. Challenges include safely suspending and maintaining turbines hundreds of meters off the ground in high winds and storms, transferring the harvested and/or generated power back to earth, and interference with aviation.
Balloons and kites were the first inventions used in aerial warfare and their primary role was reconnaissance. Balloons provided a reliable and stable means of elevating an observer high over the battlefield to obtain a birds-eye view of troop positions and movements. An early instrument of aerial intelligence collection, they were also useful for creating accurate battlefield maps, an important ingredient for battlefield success. Incendiary balloons also have a long history. The incendiary balloons carry hot air or something that can catch fire to destroy enemy territory. They could also hold small bombs for combat. The history of military ballooning dates back to the late 18th century, when the Montgolfier brothers, Joseph-Michel and Jacques-Étienne, first demonstrated the potential of hot-air balloons for military use. The first recorded military use of balloons was during the French Revolutionary Wars, when the French military used balloons to gather intelligence on the movements of the enemy. Balloons were also used during the American Civil War, where they were used for reconnaissance and communication. Balloons had a decline after several incidents in the interwar period.
An observation balloon is a type of balloon that is employed as an aerial platform for gathering intelligence and spotting artillery. The use of observation balloons began during the French Revolutionary Wars, reaching their zenith during World War I, and they continue in limited use today. Synonyms include espionage balloon, reconnaissance balloon, spy balloon, and surveillance balloon.
The Allsopp Helikite is a kite balloon or kytoon designed by Sandy Allsopp in the United Kingdom in 1993. This Helikite comprises a combination of a helium balloon and a kite to form a single, aerodynamically sound, tethered aircraft, that utilises both wind and helium for its lift.
Airborne wind energy (AWE) is the direct use or generation of wind energy by the use of aerodynamic or aerostatic lift devices. AWE technology is able to harvest high altitude winds, in contrast to wind turbines, which use a rotor mounted on a tower.
A kite balloon is a tethered balloon which is shaped to help make it stable in low and moderate winds and to increase its lift. It typically comprises a streamlined envelope with stabilising features and a harness or yoke connecting it to the main tether and a second harness connected to an observer's basket.
The Tethered Aerostat Radar System (TARS) is an American low-level airborne ground surveillance system that uses aerostats as radar platforms. Similar systems include the EL/M-2083 and JLENS.
Aeros Corp is an American manufacturer of airships based in Los Angeles, California. It was founded in 1993 by the current CEO and chief engineer, Igor Pasternak, who was born in Soviet Kazakhstan, raised in Soviet Ukraine, and moved to the U.S. after the Soviet collapse to build airships there. It currently employs more than 100 workers.
Airborne ground surveillance (AGS) refers to a class of military airborne radar system used for detecting and tracking ground targets, such as vehicles and slow moving helicopters, as opposed to Airborne early warning and control, whose primary role is detecting and tracking aircraft in flight. Antenna beam width should be very small to enhance resolution. This antenna size limitation demands high frequency of operation, to be operated in this mode. AGS radar is typically a medium or low power radar. It includes both maritime and land surveillance. Today, UAVs perform this operation, which often uses optical aids for surveillance.
A kytoon or kite balloon is a tethered aircraft which obtains some of its lift dynamically as a heavier-than-air kite and the rest aerostatically as a lighter-than-air balloon. The word is a portmanteau of kite and balloon.
An aerostat is an aircraft that remains aloft through the use of lighter-than-air gases. A narrower and more technical meaning refers only to tethered balloons.
The Joint Land Attack Cruise Missile Defense Elevated Netted Sensor System, or JLENS, was a tethered aerial detection system designed to track boats, ground vehicles, cruise missiles, manned and unmanned aircraft, and other threats. The system had four primary components: two tethered aerostats which utilized a helium/air mix, armored mooring stations, sophisticated radars, and a processing station designed to communicate with anti-missile and other ground and airborne systems. Each system was referred to as an "orbit", and two orbits were built. The Army-led joint program which fielded JLENS was designed to complement fixed-wing surveillance aircraft, saving money on crew, fuel, maintenance and other costs, and give military commanders advance warning to make decisions and provide notifications. Following cost overruns, underperformance, declining support in Congress, and public scrutiny following a snapped tether which allowed one craft moored at Aberdeen Proving Ground, Maryland to drift on a 100-mile uncontrolled descent across Pennsylvania, dragging its cable tether which damaged power lines and cut power to 20,000 homes, the program was suspended in October 2015, and completely discontinued by 2017.
Sky Dew, or High Availability Aerostat System (HAAS), is a high altitude missile defense aerostat used by Israel Defence Forces since 2022. The radar system was developed by Israel Missile Defense Organization (IMDO) and the US Missile Defense Agency (MDA). It is a tethered blimp, developed by the US TCOM company. The system is deployed in the north of Israel, a similar balloon is already used in the south. On May 15, 2024, the Aerostat was downed by a Hezbollah aircraft.
