The three critical flight dynamics parameters are the angles of rotation in three dimensions about the vehicle's center of gravity (cg), known as pitch, roll and yaw. The then-named 7N7, a twinjet successor for the trijet 727, received its first orders in August 1978. 155 (all) US Airways Flight 1549 was a regularly scheduled US Airways flight from New York City ( LaGuardia Airport ), to Charlotte and Seattle, in the United States. From Wikipedia, the free encyclopedia. The Fairchild C-119 Flying Boxcar (Navy and Marine Corps designation R4Q) was an American military transport aircraft developed from the World War II -era Fairchild C-82 Packet, designed to carry cargo, personnel, litter patients, and mechanized equipment, and to drop cargo and troops by parachute. They are well known for their series of high-performance single-engine aircraft that offer cruise speeds that surpass many twin-engine turboprop designs. Lockheed Martin C-130J Super Hercules. It also released independent short films. She then continues to. The Players Ronald (Human) Pilot Keilly (Kid) Monster (If Player activates Be the monster 3 gamepass) General Poncho General Alex Pilot. The B-1 was first envisioned in the 1960s as a platform that. The aircraft is powered by a single engine and has the capacity for one pilot and five passengers. The Mitsubishi A6M " Zero " is a long-range carrier-based fighter aircraft formerly manufactured by Mitsubishi Aircraft Company, a part of Mitsubishi Heavy Industries, and was operated by the Imperial Japanese Navy (IJN) from 1940 to 1945. The impact and resulting fire killed everyone on board. First used in the Pacific Theater of World War II in early 1942,. The C-123 Provider was designed originally as an assault glider aircraft for the United States Air Force (USAF) by Chase Aircraft as the XCG-20 (Chase designation MS-8 Avitruc) Two powered variants of the XCG-20 were developed during the early 1950s, as the XC-123 and XC-123A. The Air Tractor AT-802 is an American agricultural aircraft that may also be adapted into fire-fighting or armed versions. At age 20, while studying in Germany, Anthony Fokker built his initial aircraft, the Spin (Spider)—the first Dutch-built plane to fly in his home country. Airplane, any of a class of fixed-wing aircraft that is heavier than air, propelled by a screw propeller or a high-velocity jet, and supported by the dynamic reaction of the air against. The A6M was designated as the Mitsubishi Navy Type 0 carrier fighter (零式艦上戦闘機, rei-shiki. "Aurora" refers to the Roman goddess of dawn who. It is was picked as the 6th most funny movie in Bravo 's '100 Funniest Movies'. This page shows the parts of an airplane and their functions. The A6M was designated as the Mitsubishi Navy Type 0 carrier fighter (零式艦上戦闘機, rei-shiki. It was the successor to the Pregnant Guppy, the first of the Guppy aircraft produced by Aero Spacelines. This is a list of large aircraft, including three types: fixed wing, rotary wing, and airships. 2,391 (692 by Fairey and 1,699 by Blackburn) The Fairey Swordfish is a biplane torpedo bomber, designed by the Fairey Aviation Company. Orville and Wilbur Wright were the inventors of the first airplane. Boeing 377 Stratocruiser. The AT-802 carries a chemical hopper between the engine firewall and the cockpit. Just unfold the piece of paper the same way you folded it. 64 (5 YF-117As, 59 F-117As) Developed from. The Boeing E-6 Mercury (formerly Hermes) is an airborne command post and communications relay based on the Boeing 707-300. Jul 2, 1980 · Airplane!: Directed by Jim Abrahams, David Zucker, Jerry Zucker. Although the Curtiss JN series was originally produced as a training aircraft for the US Army, the "Jenny" (the common nickname derived from "JN. Nobody accelerates aerospace innovation like Lockheed Martin. A U. STOL aircraft, including those used in scheduled passenger airline. The New Midsize Airplane ( NMA ), or New Midsize Aircraft, [1] (culturally referred to as the Boeing 797) [2] is a concept airliner proposed by Boeing to fill the middle of the market segment. The C-17 carries forward the name of two previous piston. A 1786 depiction of the Montgolfier brothers ' balloon. As the air accelerates downward, the wing (and the plane) move upward. Earl Shilton, Leicester: Midland Pub. " (originally titled " ") is a song that was written by Darby Slick. In 1946, the Fulton FA-2 Airphibian was an American made flying car designed by Robert Edison Fulton Jr. Airplane! is an American parody comedy movie made in 1980. The Boeing 737 Next Generation, commonly abbreviated as 737NG, or 737 Next Gen, is a narrow-body aircraft powered by two jet engines and produced by Boeing Commercial Airplanes. 21 [1] [2] The Northrop Grumman B-2 Spirit, also known as the Stealth Bomber, is an American heavy strategic bomber, featuring low-observable stealth technology designed to penetrate dense anti-aircraft defenses. The previous ten news annoucements will go into the Archived News Page. The North American B-25 Mitchell is an American medium bomber that was introduced in 1941 and named in honor of Brigadier General William "Billy" Mitchell, a pioneer of U. See below. org concluded, "The evidence supporting the Aurora is. Airplane! is a 1980 film that spoofs airport disaster movies. Derived from the Boeing 707 airliner, it provides all-weather surveillance, command, control, and communications, and is used by the United States Air Force,. Within the atmosphere, air suitable for use in photosynthesis by terrestrial plants and breathing of terrestrial animals is found only in Earth's. The Airbus A320 family was the first airliner to feature a full glass cockpit and digital fly-by-wire flight control system. 155 (all) US Airways Flight 1549 was a regularly scheduled US Airways flight from New York City ( LaGuardia Airport ), to Charlotte and Seattle, in the United States. An airplane, also known as an aeroplane or just plane, is a fixed-wing aircraft. Stargazer is a Lockheed L-1011 TriStar built in 1974, that was modified in 1994 for use by Orbital Sciences (now part of Northrop Grumman) as a mother ship launch pad for the Pegasus launch vehicle. Longitudinal plane, or roll plane. The Piper PA-18 Super Cub is a two-seat, single-engine monoplane. The Airplane Song is an original Barney song that first appeared in "Going Places!". Capacity: 219–318 passengers. Fairey Firefly II M biplane floatplane. It can carry up to 3,200 lb (1,450 kg) of external. The Fairchild C-119 Flying Boxcar (Navy and Marine Corps designation R4Q) was an American military transport aircraft developed from the World War II -era Fairchild C-82 Packet, designed to carry cargo, personnel, litter patients, and mechanized equipment, and to drop cargo and troops by parachute. The hydrogen-powered Tu-155 prototype made its first flight on 15 April 1988. In aeronautics, an aircraft propeller, also called an airscrew, converts rotary motion from an engine or other power source into a swirling slipstream which pushes the propeller forwards or backwards. Autochrome Lumière of a Nieuport Fighter in , France 1917. The intention was to produce a jet engine that would heat compressed air with heat from fission, instead of heat from burning fuel. In military conflict, the role of fighter. 79 in) Hispano M2. It is was picked as the 6th most funny movie in Bravo 's '100 Funniest Movies'. It first appeared on their album Surrealistic Pillow with a live version later appearing on the expanded rerelease of Bless Its Pointed Little Head. List of aircraft of the Royal Australian Air Force. Number built. Turn the plane over and fold the other side. In 1935, Douglas produced a larger version called the DC-3, which became one of the most successful aircraft in history. This list of missing aircraft includes aircraft that have disappeared and whose. Acute anxiety caused by flying can be treated with anti-anxiety medication. The P-40 design was a modification of the previous Curtiss P-36 Hawk which reduced development time and enabled a rapid entry into production and operational service. From the fuselage, or main body of the plane, to the wings, or the fins of the plane, to the rudder, which helps. Its maiden flight occurred on January 10,. The Gripen has a delta wing and canard configuration with relaxed stability design and fly-by-wire flight controls. Lesson Summary. Aircraft Communications Addressing and Reporting System. It also changes with variations in atmospheric pressure, temperature and humidity. 5,449 (310) 577 (320) Developed into. The de Havilland Canada DHC-4 Caribou (designated by the United States military as the CV-2 and later C-7 Caribou) is a Canadian specialized cargo aircraft with short takeoff and landing ( STOL) capability. Louis de Monge. The Airbus A330 is a wide-body aircraft developed and produced by Airbus. Jefferson Airplane Takes Off is the debut studio album by the American rock band Jefferson Airplane, released on 15 August 1966 by RCA Victor. o Piloto Sumiu! / Portugal: O Aeroplano) é um filme americano de 1980 do gênero comédia satírica de catástrofe dirigido e escrito por Jim Abrahams e pelos irmãos David e Jerry Zucker, [ 3] sendo distribuído pela Paramount Pictures. 2: Twin-Engined Fighters, Attack Aircraft and Bombers. A 'right-handed' propeller on a merchant vessel, which rotates clockwise to propel the ship forward. Curtiss XP-42. The fixed wings of a delta -shaped kite are not rigid. A Cubana Tupolev 204E in 2007. 13 August 1932. Sukhoi Su-37. At 7:36 pm on November 14, 1970, the aircraft crashed into a hill just short of the Tri-State Airport, killing all 75. Leicester: Midland Counties Publications. Training in Pipers. The An-124 is the. The propellers of a C-130J Super Hercules military transport aircraft. [1] These speeds are derived from data obtained by aircraft designers and manufacturers during flight testing for aircraft type-certification. 'Transport-20 Kunpeng') is a large military transport aircraft developed by the Xi'an Aircraft Industrial Corporation for the People's Republic of China (PRC). Number built. They failed to recover the plane from the stall, and the plane crashed into the North Atlantic Ocean at 02:14 UTC, killing all 228. Airplanes are transportation devices which are designed to move people and cargo from one place to another. That was the day that Orville won the toss of the coin. Since 2019, Airbus is the world's largest manufacturer of airliners as well as the leading helicopter manufacturer. McDonnell Douglas F/A-18 Hornet in Australian service. Lockheed based it on the L-188 Electra commercial airliner; it is easily distinguished from the Electra by its distinctive tail stinger or "MAD" boom, used for the. A short takeoff and landing ( STOL) aircraft is a conventional fixed-wing aircraft that has short runway requirements for takeoff and landing. Still in production, the Islander is one of the best-selling commercial aircraft types produced in Europe. A flap is a high-lift device used to reduce the stalling speed of an aircraft wing at a given weight. Flatten the fold using your knuckle or fingernail so it holds in place. Audio recording of Spitfire fly-past at the 2011 family day at RAF Halton, Buckinghamshire. The General Dynamics-Grumman F-111B is a former long-range carrier-based interceptor aircraft planned as a follow-on to the F-4 Phantom II for the United States Navy (USN). UPS Airlines is a major American cargo airline based in Louisville, Kentucky. Wright Flyer (also known as the Kitty Hawk [3] [4]) made the first sustained flight by a manned heavier-than-air powered and controlled aircraft—an airplane —on December 17, 1903. Built by Douglas Aircraft Company during World War II, the Invader also saw service during several major Cold War conflicts. Airbus Fleet. The Curtiss P-36 Hawk, also known as the Curtiss Hawk Model 75, is an American-designed and built fighter aircraft of the 1930s and 40s. The Boeing KC-46 Pegasus is an American military aerial refueling and strategic military transport aircraft developed by Boeing from its 767 jet airliner. Our systemic approach to aviation combines world-class training and state-of-the-art technology, creating the most agile and effective aircraft ever to fly the skies. The following 82 files are in this category, out of 82 total. The company and development project were officially announced in December 2011 by Microsoft co-founder Paul Allen and Scaled Composites founder. Designed for flight training and personal use—and specifically developed to. o Piloto Sumiu! / Portugal: O Aeroplano) é um filme americano de 1980 do gênero comédia satírica de catástrofe dirigido e escrito por Jim Abrahams e pelos irmãos David e Jerry Zucker, [ 3] sendo distribuído pela Paramount Pictures. [4] The Boeing Company ( / ˈboʊɪŋ /) is an American multinational corporation that designs, manufactures, and sells airplanes, rotorcraft, rockets, satellites, telecommunications equipment, and missiles worldwide. 2: Twin-Engined Fighters, Attack Aircraft and Bombers. Aviation in World War I. FlightGear has a wide variety of modern and retired military jets available, highlighted by features such as air-to-air refueling from the venerable KC-135 and the ability to simulate A-10 ordnance release. During the war the C-47 was used for troop transport, cargo, paratrooper, for towing gliders and military cargo parachute drops. F-WTSS (production designation 001) was the first Concorde to fly, on 2 March 1969, and was retired on arrival at the French air museum at Le Bourget Airport on 19 October 1973, having made 397 flights covering 812 hours, of which 255 hours were at supersonic speeds. With Kareem Abdul-Jabbar, Lloyd Bridges, Peter Graves, Julie Hagerty. Number built. And nothing feels different. Hold the left mouse button and move it to move the spaceship. Cessna 340. Nov 17, 2023 · Airplane! was an immediate critical and commercial success, grossing more than $83 million on an estimated budget of $3. List of United States Air Force aircraft designations (1919-1962) List of United States Navy aircraft designations (pre-1962) List of United States Army aircraft designations (1956-1962) List of United States Tri-Service aircraft designations. Air shows sprang up around the country, with air races, acrobatic stunts, and feats of air superiority. The three critical flight dynamics parameters are the angles of rotation in three dimensions about the vehicle's center of gravity (cg), known as pitch, roll and yaw. Development of the Vampire as an experimental aircraft began in. o Piloto Sumiu! / Portugal: O Aeroplano) é um filme americano de 1980 do gênero comédia satírica de catástrofe dirigido e escrito por Jim Abrahams e pelos irmãos David e Jerry Zucker, [ 3] sendo distribuído pela Paramount Pictures. Production models of the F-111 had roles that included attack (e. The De Havilland Canada DHC-8, [2] commonly known as the Dash 8, is a series of turboprop -powered regional airliners, introduced by de Havilland Canada (DHC) in 1984. Contact with the aircraft, a Boeing 777-200ER, was lost when it was about 50 km (31 mi) from. The Vickers Viscount is a British medium-range turboprop airliner first flown in 1948 by Vickers-Armstrongs. The F-117 Nighthawk was the first operational aircraft explicitly. It was originally recorded by , and later by Jefferson Airplane Rolling Stone magazine ranked Jefferson Airplane's version No. Notify the tower that you're ready for takeoff. For a history of military aviation, see military aircraft; for lighter-than-air flight, see airship. The bomber can drop conventional and thermonuclear weapons. For an account of the development of the airplane and the advent of civil aviation see history of flight. The Cub is Piper Aircraft's most-produced model, with nearly 20,000 built in the United States. A flight data recorder (FDR; also ADR, for accident data recorder) is an electronic device employed to record instructions sent to any electronic systems on an aircraft. [1] During the Cold War, the United States and Soviet Union researched nuclear-powered bomber aircraft, the greater. A reduced-gravity aircraft is a type of fixed-wing aircraft that provides brief near-weightless environments for training astronauts, conducting research, and making gravity-free movie shots. Click here to play! 🥥🏝️; Featured Article of the Week. Fold the top two corners in. Trump Force One. US Air Forces video: Flying Tigers Bite Back The First American Volunteer Group (AVG) of the Republic of China Air Force, nicknamed the Flying Tigers, was formed to help oppose the Japanese invasion of China. The Dassault Rafale ( French pronunciation: [ʁafal], literally meaning "gust of wind", [2] or "burst of fire" in a more military sense) [3] is a French twin-engine, canard delta wing, multirole fighter aircraft designed and built by Dassault Aviation. The Gulfstream G650 is a large business jet produced by Gulfstream Aerospace. 2 (1914) Bristol Scout (1914) Caproni Ca. Most supersonic aircraft have been military or experimental aircraft. Designed as an improvement on the F2F, it entered service in 1936 as the last biplane to be delivered to any American military air arm. The Lockheed F-117 Nighthawk is a retired American single-seat, subsonic twin-engine stealth attack aircraft developed by Lockheed's secretive Skunk Works division and operated by the United States Air Force (USAF). (August 19, 1871 – January 30, 1948) and (April 16, 1867 – May 30, 1912), were American pioneers generally credited with inventing, building, and flying the world's first successful motor-operated with the Wright Flyer on December 17, 1903, four miles (6 km) south of Kitty Hawk. The Antonov An-124 Ruslan (Russian: Антонов Ан-124 Руслан; Ukrainian: Ан-124 Руслан, lit. Airplane! is a 1980 film that spoofs airport disaster movies. A light aircraft is an aircraft that has a maximum gross takeoff weight of 12,500 lb (5,670 kg) or less. It first flew in the United States in October 1990 and is manufactured by Air Tractor. Its simplicity, affordability and popularity invokes comparisons to the. The B-52 was designed and built by Boeing, which has continued to provide support and upgrades. de Havilland Venom. 98 Mosquito is a British twin-engined, multirole combat aircraft, introduced during the Second World War. The list of aircraft of World War II includes all the aircraft used by those countries which were at war during World War from the period between their joining the conflict and the conflict ending for them. "Volunteers" is a Jefferson Airplane single from 1969 that was released to promote the album Volunteers two months before the album's release. It manufactures single-engined piston-powered general aviation aircraft. Keep the blades on the outside of the plane. LTV A-7 Corsair II. A hydrogen-powered aircraft is an aeroplane that uses hydrogen fuel as a power source. They improve safety by allowing the pilot to fly the aircraft in level flight, and make turns. vonage app download, cuckold wife porn
SKYFIGHTERS —Redeem for 55k Cash. . Airplane wiki
Production models of the F-111 had roles that included attack (e. Indonesian Aerospace N-219. The Extra 300L is a Lycoming AEIO-540-powered two-seat aircraft, with low-mounted wing and shorter fuselage. The Boeing EA-18G Growler is an American carrier-based electronic warfare aircraft, a specialized version of the two-seat F/A-18F Super Hornet. Known as the Aurora, it flies out of legendary Area 51 and is cloaked in secrecy. The McDonnell Douglas DC-10 is an American trijet wide-body aircraft manufactured by McDonnell Douglas. Number built. Atmosphere is a mixture of about 78% nitrogen, 21% of oxygen. Due to its efficient, high-utility design, the PC-12 is. airplane: [noun] a powered heavier-than-air aircraft with fixed wings from which it derives most of its lift. The Boeing 2707 was an American supersonic passenger airliner project during the 1960s. 'dream' or 'inspiration'; NATO reporting name: Cossack) was a strategic airlift cargo aircraft designed and produced by the Antonov Design Bureau in the Soviet Union. ' Ruslan '; NATO reporting name: Condor) is a large, strategic airlift, four-engined aircraft that was designed in the 1980s by the Antonov design bureau in the Ukrainian SSR, then part of the Soviet Union (USSR). Airplane (commonly known as Airplane 1 or Airplane! 1) is the first game in the Airplane Series. Some other aircrew members, such as navigators or flight engineers, are also considered aviators because they are involved in operating the aircraft's navigation and engine systems. Number built. Controlled Impact Demonstration. The H. You should not be here! The Crystal Ball is simply a pink translucent floating orb with a face on it. It is a development of the British Aerospace 125, and was assembled by Hawker Beechcraft. It was initially produced as the Douglas DC-9 prior to August 1967, after which point the company had merged with McDonnell Aircraft to become McDonnell Douglas. The Boeing F/A-18E and F/A-18F Super Hornet are supersonic twin-engine, carrier-capable, multirole fighter aircraft variants derived from the McDonnell Douglas F/A-18 Hornet series. After introducing the in October 1958, times its size, to reduce its by 30%. Instead, the autopilot assists the operator's control of the vehicle, allowing. 1,258 (as of March 31, 2019) [1] Developed from. The Immelmann turn was an effective maneuver in the early part of the war but as aircraft technology advanced. The North American F-82 Twin Mustang is the last American piston-engined fighter ordered into production by the United States Air Force. This article tells the story of the invention of the airplane and the development of civil aviation from piston-engine airplanes to jets. Douglas DC-6. The Northrop Grumman B-2 Spirit, also known as the Stealth Bomber, is an American heavy strategic bomber, featuring low-observable stealth technology designed to penetrate dense anti-aircraft defenses. During the war the C-47 was used for troop transport, cargo, paratrooper, for towing gliders and military cargo parachute drops. : aircraft) is a vehicle that is able to fly by gaining support from the air. airplane: [noun] a powered heavier-than-air aircraft with fixed wings from which it derives most of its lift. Make a vertical valley fold. Instead, the autopilot assists the operator's control of the vehicle, allowing. In military conflict, the role of fighter. After introducing the 747-400, Boeing considered larger 747 versions as alternatives to the proposed double-deck Airbus A3XX, later developed as the A380. (2014) Aerial firefighting, also known as waterbombing, is the use of aircraft and other aerial resources to combat wildfires. The McDonnell Douglas MD-11 is an American tri-jet wide-body airliner manufactured by American manufacturer McDonnell Douglas (MDC) and later by Boeing. Created as a day fighter by Lockheed as one of the "Century Series" of fighter aircraft for the United States Air Force (USAF), it was developed into an all. Conroy Turbo-Three. The Mustang was designed in April 1940 by a team headed by James H. Through its history the company has had many American owners and subsequent bankruptcies. The Boeing 707 is an American long-range narrow-body airliner, the first jetliner developed and produced by Boeing Commercial Airplanes. Tupolev Tu-22. Boeing 377 Stratocruiser. Cruise is the second spin-off game of the Airplane series, after Castle. By the time it entered commercial service in 1940, many airlines were canceling orders for aircraft. The then-named 7N7, a twinjet successor for the trijet 727, received its first orders in August 1978. The Cessna 172 Skyhawk is an American four-seat, single-engine, high wing, fixed-wing aircraft made by the Cessna Aircraft Company. Trainer aircraft. Based on the North American P-51 Mustang, the F-82 was originally designed as a long-range escort fighter for the Boeing B-29 Superfortress in World War II. An airplane ( American English ), or aeroplane ( Commonwealth English ), informally plane, is a fixed-wing aircraft that is propelled forward by thrust from a jet engine, propeller, or rocket engine. Today I turn 18. Number built. A military aircraft is any fixed-wing or rotary-wing aircraft that is operated by a legal or insurrectionary military of any type. So far, the Mars helicopter Ingenuity is the only aircraft [2] [3] ever to fly on Mars, completing 67 successful flights. Number built. Cessna 152. The Gripen has a delta wing and canard configuration with relaxed stability design and fly-by-wire flight controls. The HAL Tejas (lit. The Concorde (/ ˈ k ɒ ŋ k ɔːr d /) is a retired Franco-British supersonic airliner jointly developed and manufactured by Sud Aviation (later Aérospatiale) and the British Aircraft Corporation (BAC). The ICON A5 is an American amphibious light-sport aircraft (LSA) designed and produced by ICON Aircraft. The ICON A5 is an American amphibious light-sport aircraft (LSA) designed and produced by ICON Aircraft. The Tupolev Tu-95 (Russian: Туполев Ту-95; NATO reporting name: "Bear") is a large, four-engine turboprop-powered strategic bomber and missile platform. Airport 1975 (also known as Airport '75) is a 1974 American air disaster film and the first sequel to the successful 1970 film Airport. Flight dynamics is the science of air vehicle orientation and control in three dimensions. It had been ordered by Eastern Air Lines, but after Eastern canceled its orders for Boeing 747s, the plane was purchased new by Trans World Airlines. C-5B: 1985–1989. The Players The Monster President Ronald Trump The Agent Pilot Keilly Chef (only mentioned) Headless Horseman For a transcript, go here Sometime after the flight. It has mass and weight, because it is matter. This aircraft is named in Guinness World Records, 1997, as the fastest in this category with a speed of 623 mph (1,003 km/h) (Mach 0. United Airlines is its first major corporate partner, having ordered. During the war the C-47 was used for troop transport, cargo, paratrooper, for towing gliders and military cargo parachute drops. The P-40 design was a modification of the previous Curtiss P-36 Hawk which reduced development time and enabled a rapid entry into production and operational service. Today I turn 18. Air is a mixture of many gases and tiny dust particles. Concorde. It was the last piston-engined bomber built by Boeing for the United States Air. Piper PA-48 Enforcer. 5 m 2) Empty weight: 41,276 lb (18,722 kg) Max takeoff weight: 67,500 lb (30,617 kg) Powerplant: 4 × Rolls-Royce Dart Mk 525 turboprop, 1,990 hp (1,484 kW) each. Written and directed by Jim Abrahams, David Zucker and Jerry Zucker. Unfold the paper after you crease it so the you now have a piece of paper with a vertical valley crease. World War I was the first major conflict involving the large-scale use of aircraft. A military aircraft is any fixed-wing or rotary-wing aircraft that is operated by a legal or insurrectionary military of any type. The stretched 747 Advanced was launched as the 747-8 on November 14, 2005, for a market forecast of. The bomber was reported as being designated Tu-26 by western intelligence at one time. It is a prequel to Airplane and Airplane 2, telling a story of government soldiers on a manhunt, and explaining much of the backstory. . joi hypnosis