Jet aircraft

Jet aircraft

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A jet aircraft is an aircraft
Aircraft
An aircraft is a vehicle that is able to fly by gaining support from the air, or, in general, the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines.Although...

 (nearly always a fixed-wing aircraft
Fixed-wing aircraft
A fixed-wing aircraft is an aircraft capable of flight using wings that generate lift due to the vehicle's forward airspeed. Fixed-wing aircraft are distinct from rotary-wing aircraft in which wings rotate about a fixed mast and ornithopters in which lift is generated by flapping wings.A powered...

) propelled by jet engine
Jet engine
A jet engine is a reaction engine that discharges a fast moving jet to generate thrust by jet propulsion and in accordance with Newton's laws of motion. This broad definition of jet engines includes turbojets, turbofans, rockets, ramjets, pulse jets...

s. Jet aircraft generally fly much faster than propeller
Propeller (aircraft)
Aircraft propellers or airscrews convert rotary motion from piston engines or turboprops to provide propulsive force. They may be fixed or variable pitch. Early aircraft propellers were carved by hand from solid or laminated wood with later propellers being constructed from metal...

-powered aircraft and at higher altitudes – as high as 10000–15000 m (32,808.4–49,212.6 ft). At these altitudes, jet engines achieve maximum efficiency over long distances. The engines in propeller-powered aircraft achieve their maximum efficiency at much lower altitudes. Some jet aircraft can move faster than sound.

Two engineers, Frank Whittle in the United Kingdom and Hans von Ohain in Germany, developed the concept independently during the late 1930s. The concept had been discussed as early as August 1928 by Frank Whittle
Frank Whittle
Air Commodore Sir Frank Whittle, OM, KBE, CB, FRS, Hon FRAeS was a British Royal Air Force engineer officer. He is credited with independently inventing the turbojet engine Air Commodore Sir Frank Whittle, OM, KBE, CB, FRS, Hon FRAeS (1 June 1907 – 9 August 1996) was a British Royal Air...

, but Hans von Ohain
Hans von Ohain
Hans Joachim Pabst von Ohain was a German engineer, one of the inventors of jet propulsion.Frank Whittle, who patented in 1930 in the United Kingdom, and Hans von Ohain, who patented in 1936 in Germany, developed the concept independently during the late 1930s...

 also wrote in February 1936 to Ernst Heinkel
Ernst Heinkel
Dr. Ernst Heinkel was a German aircraft designer, manufacturer, Wehrwirtschaftführer in the Third Reich, and member of the Nazi party. His company Heinkel Flugzeugwerke produced the Heinkel He 178, the world's first turbojet aircraft and jet plane, and the Heinkel He 176, the first rocket aircraft...

, telling him of the design and its possibilities. However, it can be argued that A. A. Griffith
Alan Arnold Griffith
Alan Arnold Griffith was an English engineer, who, among many other contributions, is best known for his work on stress and fracture in metals that is now known as metal fatigue, as well as being one of the first to develop a strong theoretical basis for the jet engine.-Early work:A. A...

, who published a paper in July 1926 on compressors and turbines, also deserves credit.


History



A number of jet powerplants were suggested from the first instances of powered flight. René Lorin
René Lorin
René Lorin , a graduate of the Ecole Centrale Paris, invented the ramjet. In 1908 he patented a subsonic ramjet design.Lorin published the principles of a ramjet in articles in the journal L'Aérophile from 1908 to 1913, expressing the idea that the exhaust from internal combustion engines could be...

, Morize, Harris proposed systems for creating a jet efflux. In 1910 Henri Coandă
Henri Coanda
Henri Marie Coandă was a Romanian inventor, aerodynamics pioneer and builder of an experimental aircraft, the Coandă-1910 described by Coandă in the mid-1950s as the world's first jet, a controversial claim disputed by some and supported by others...

 filed a patent on a jet propulsion system which used piston-engine exhaust gases to add heat to an otherwise pure air stream compressed by rotating fan blades in a duct.

The "turbojet", was invented in the 1930s, independently by Frank Whittle
Frank Whittle
Air Commodore Sir Frank Whittle, OM, KBE, CB, FRS, Hon FRAeS was a British Royal Air Force engineer officer. He is credited with independently inventing the turbojet engine Air Commodore Sir Frank Whittle, OM, KBE, CB, FRS, Hon FRAeS (1 June 1907 – 9 August 1996) was a British Royal Air...

 and Hans von Ohain
Hans von Ohain
Hans Joachim Pabst von Ohain was a German engineer, one of the inventors of jet propulsion.Frank Whittle, who patented in 1930 in the United Kingdom, and Hans von Ohain, who patented in 1936 in Germany, developed the concept independently during the late 1930s...

. The first turbojet aircraft to fly was the Heinkel He 178
Heinkel He 178
|-See also:*List of firsts in aviation-Bibliography:* Warsitz, Lutz: The First Jet Pilot - The Story of German Test Pilot Erich Warsitz, Pen and Sword Books Ltd., England, 2009, ISBN 9781844158188.-External links:...

 prototype
Prototype
A prototype is an early sample or model built to test a concept or process or to act as a thing to be replicated or learned from.The word prototype derives from the Greek πρωτότυπον , "primitive form", neutral of πρωτότυπος , "original, primitive", from πρῶτος , "first" and τύπος ,...

 of the German
Nazi Germany
Nazi Germany , also known as the Third Reich , but officially called German Reich from 1933 to 1943 and Greater German Reich from 26 June 1943 onward, is the name commonly used to refer to the state of Germany from 1933 to 1945, when it was a totalitarian dictatorship ruled by...

 Air Force, the Luftwaffe
Luftwaffe
Luftwaffe is a generic German term for an air force. It is also the official name for two of the four historic German air forces, the Wehrmacht air arm founded in 1935 and disbanded in 1946; and the current Bundeswehr air arm founded in 1956....

, on August 27, 1939.

The first flight of a jet engined aircraft to come to popular attention was the Italian
Kingdom of Italy (1861–1946)
The Kingdom of Italy was a state forged in 1861 by the unification of Italy under the influence of the Kingdom of Sardinia, which was its legal predecessor state...

 Caproni Campini N.1 motorjet
Motorjet
A motorjet is a rudimentary type of jet engine which is sometimes referred to as thermojet, a term now commonly used to describe a particular and completely unrelated pulsejet design.- Design :...

 prototype that flew on August 27, 1940. It was the first jet aircraft recognised by the Fédération Aéronautique Internationale
Fédération Aéronautique Internationale
The Fédération Aéronautique Internationale is the world governing body for air sports and aeronautics and astronautics world records. Its head office is in Lausanne, Switzerland. This includes man-carrying aerospace vehicles from balloons to spacecraft, and unmanned aerial vehicles...

 (at the time the German He 178 program was still kept secret). Campini had proposed the motorjet in 1932.

The British experimental Gloster E.28/39
Gloster E.28/39
|-See also:-References:NotesBibliography* James, Derek N. Gloster Aircraft since 1917. London: Putnam, 1987. ISBN 0-85177-807-0.* Mondey, David. The Hamlyn Concise Guide to British Aircraft of World War II. London: Chancellor Press, 1994. ISBN 1-85152-668-4.* Morgan, Eric B. "A New Concept of...

 first took to the air on May 15, 1941, powered by Sir Frank Whittle's turbojet. After the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 was shown the British work, it produced the Bell XP-59A with a version of the Whittle engine built by General Electric
General Electric
General Electric Company , or GE, is an American multinational conglomerate corporation incorporated in Schenectady, New York and headquartered in Fairfield, Connecticut, United States...

, which flew on October 1, 1942.

The first operational jet fighter
Fighter aircraft
A fighter aircraft is a military aircraft designed primarily for air-to-air combat with other aircraft, as opposed to a bomber, which is designed primarily to attack ground targets...

 was the Messerschmitt Me 262
Messerschmitt Me 262
The Messerschmitt Me 262 Schwalbe was the world's first operational jet-powered fighter aircraft. Design work started before World War II began, but engine problems prevented the aircraft from attaining operational status with the Luftwaffe until mid-1944...

, made by Germany during late World War II. It was the fastest conventional aircraft of World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

 – although the rocket-powered Messerschmitt Me 163
Messerschmitt Me 163
The Messerschmitt Me 163 Komet, designed by Alexander Lippisch, was a German rocket-powered fighter aircraft. It is the only rocket-powered fighter aircraft ever to have been operational. Its design was revolutionary, and the Me 163 was capable of performance unrivaled at the time. Messerschmitt...

 Komet was faster. It had first flown in 1941 but mass production started in 1944 with the first squadrons operational that year, too late for a decisive effect on the outcome of the war. About the same time, mid 1944, the United Kingdom's Gloster Meteor
Gloster Meteor
The Gloster Meteor was the first British jet fighter and the Allies' first operational jet. It first flew in 1943 and commenced operations on 27 July 1944 with 616 Squadron of the Royal Air Force...

 was being committed to defence of the UK against the V1 flying bomb – itself a jet-powered aircraft – and then ground-attack operations over Europe in the last months of the war. In 1944 Germany introduced into service the Arado Ar 234
Arado Ar 234
The Arado Ar 234 was the world's first operational jet-powered bomber, built by the German Arado company in the closing stages of World War II. Produced in very limited numbers, it was used almost entirely in the reconnaissance role, but in its few uses as a bomber it proved to be nearly impossible...

 jet reconnaissance and bomber, though chiefly used in the former role.
USSR tested its own Bereznyak-Isayev BI-1
Bereznyak-Isayev BI-1
Soviet research and development of rocket-powered aircraft began with Sergey Korolev's GIRD-6 project in 1932. His interest in stratospheric flight was also shared by Marshal Mikhail Tukhachevsky who supported this early work...

 in 1942, but the project was scrapped by Joseph Stalin
Joseph Stalin
Joseph Vissarionovich Stalin was the Premier of the Soviet Union from 6 May 1941 to 5 March 1953. He was among the Bolshevik revolutionaries who brought about the October Revolution and had held the position of first General Secretary of the Communist Party of the Soviet Union's Central Committee...

 in 1945. The Imperial Japanese Navy
Imperial Japanese Navy
The Imperial Japanese Navy was the navy of the Empire of Japan from 1869 until 1947, when it was dissolved following Japan's constitutional renunciation of the use of force as a means of settling international disputes...

 also developed jet aircraft in 1945, including the Nakajima J9Y Kikka
Nakajima Kikka
|-References:NotesBibliography* Famous Aircraft of the World no.76: Japanese Army Experimental Fighters . Tokyo: Bunrin-Do, August 1976....

, a crude copy of the Me 262. By the end of 1945, the US had introduced their next jet fighter, the Lockheed P-80 Shooting Star into service and the UK its second fighter design, the de Havilland Vampire
De Havilland Vampire
The de Havilland DH.100 Vampire was a British jet-engine fighter commissioned by the Royal Air Force during the Second World War. Following the Gloster Meteor, it was the second jet fighter to enter service with the RAF. Although it arrived too late to see combat during the war, the Vampire served...



The US introduced the North American B-45 Tornado, their first jet bomber, into service in 1948. Although capable of carrying nuclear weapons it was used for reconnaissance over Korea.

On November 8, 1950, during the Korean War
Korean War
The Korean War was a conventional war between South Korea, supported by the United Nations, and North Korea, supported by the People's Republic of China , with military material aid from the Soviet Union...

, United States Air Force
United States Air Force
The United States Air Force is the aerial warfare service branch of the United States Armed Forces and one of the American uniformed services. Initially part of the United States Army, the USAF was formed as a separate branch of the military on September 18, 1947 under the National Security Act of...

 Lt. Russell J. Brown, flying in an F-80
P-80 Shooting Star
The Lockheed P-80 Shooting Star was the first jet fighter used operationally by the United States Army Air Forces. Designed in 1943 as a response to the German Messerschmitt Me-262 jet fighter, and delivered in just 143 days from the start of the design process, production models were flying but...

, intercepted two North Korea
North Korea
The Democratic People’s Republic of Korea , , is a country in East Asia, occupying the northern half of the Korean Peninsula. Its capital and largest city is Pyongyang. The Korean Demilitarized Zone serves as the buffer zone between North Korea and South Korea...

n MiG-15s near the Yalu River
Yalu River
The Yalu River or the Amnok River is a river on the border between North Korea and the People's Republic of China....

 and shot them down in the first jet-to-jet dogfight
Dogfight
A dogfight, or dog fight, is a form of aerial combat between fighter aircraft; in particular, combat of maneuver at short range, where each side is aware of the other's presence. Dogfighting first appeared during World War I, shortly after the invention of the airplane...

 in history.

The UK put the English Electric Canberra
English Electric Canberra
The English Electric Canberra is a first-generation jet-powered light bomber manufactured in large numbers through the 1950s. The Canberra could fly at a higher altitude than any other bomber through the 1950s and set a world altitude record of 70,310 ft in 1957...

 into service in 1951 as a light bomber
Light bomber
A light bomber is a relatively small and fast class of military bomber aircraft which were primarily employed before the 1950s. Such aircraft would typically not carry more than one ton of ordnance....

. It was designed to fly higher and faster than any interceptor
Interceptor aircraft
An interceptor aircraft is a type of fighter aircraft designed specifically to prevent missions of enemy aircraft, particularly bombers and reconnaissance aircraft. Interceptors generally rely on high speed and powerful armament in order to complete their mission as quickly as possible and set up...

.

BOAC
Boac
Boac may refer to:* Boac, Marinduque, a municipality in the Southern Philippines* Boac , an American rapper* British Overseas Airways Corporation, a former British state-owned airline...

 operated the first commercial jet service, from London
London
London is the capital city of :England and the :United Kingdom, the largest metropolitan area in the United Kingdom, and the largest urban zone in the European Union by most measures. Located on the River Thames, London has been a major settlement for two millennia, its history going back to its...

 to Johannesburg
Johannesburg
Johannesburg also known as Jozi, Jo'burg or Egoli, is the largest city in South Africa, by population. Johannesburg is the provincial capital of Gauteng, the wealthiest province in South Africa, having the largest economy of any metropolitan region in Sub-Saharan Africa...

, in 1952 with the de Havilland Comet
De Havilland Comet
The de Havilland DH 106 Comet was the world's first commercial jet airliner to reach production. Developed and manufactured by de Havilland at the Hatfield, Hertfordshire, United Kingdom headquarters, it first flew in 1949 and was a landmark in aeronautical design...

 jetliner
Jetliner
Jetliner are an alternative rock band from the USA. They focus on melodic piano based rock and have been compared to Queen and early Elton John, being heavily influenced by early 70s rock. Composed of Adam Paskowitz of The Flys, son of Doc Paskowitz, on piano and lead vocals, Jeff Kluesner on...

. The Comet was initially ahead of rivals, but a series of crashes gave time for the Boeing 707
Boeing 707
The Boeing 707 is a four-engine narrow-body commercial passenger jet airliner developed by Boeing in the early 1950s. Its name is most commonly pronounced as "Seven Oh Seven". The first airline to operate the 707 was Pan American World Airways, inaugurating the type's first commercial flight on...

 to enter service in 1958 and dominate the market for civilian airliners.

Turbofan
Turbofan
The turbofan is a type of airbreathing jet engine that is widely used for aircraft propulsion. A turbofan combines two types of engines, the turbo portion which is a conventional gas turbine engine, and the fan, a propeller-like ducted fan...

 aircraft began entering service in the 1960s and 1970s, and this is the most common type of jet in use today.

The Tu-144 supersonic transport
Supersonic transport
A supersonic transport is a civilian supersonic aircraft designed to transport passengers at speeds greater than the speed of sound. The only SSTs to see regular service to date have been Concorde and the Tupolev Tu-144. The last passenger flight of the Tu-144 was in June 1978 with its last ever...

 was the fastest commercial jet plane at Mach 2.35 (1,555 mph, 2,503 km/h). It went into service in 1975, but soon stopped flying. The Mach 2 Concorde
Concorde
Aérospatiale-BAC Concorde was a turbojet-powered supersonic passenger airliner, a supersonic transport . It was a product of an Anglo-French government treaty, combining the manufacturing efforts of Aérospatiale and the British Aircraft Corporation...

 aircraft entered service in 1976 and flew for 27 years.

The fastest military jet plane was the SR-71 Blackbird
SR-71 Blackbird
The Lockheed SR-71 "Blackbird" was an advanced, long-range, Mach 3+ strategic reconnaissance aircraft. It was developed as a black project from the Lockheed A-12 reconnaissance aircraft in the 1960s by the Lockheed Skunk Works. Clarence "Kelly" Johnson was responsible for many of the...

 at Mach 3.35 (2,275 mph, 3,661 km/h).

Other jets


Most people use the term 'jet aircraft' to denote gas turbine based airbreathing jet engine
Airbreathing jet engine
An airbreathing jet engine is a jet engine propelled by a jet of hot exhaust gases formed from air that is drawn into the engine via an inlet duct....

s, but rockets and scramjets are both also propelled by jet propulsion.

The fastest airbreathing jet aircraft is the unmanned X-43 scramjet at around Mach 9–10. The fastest manned (rocket) aircraft is the X-15 at Mach 6.85.

The Space Shuttle
Space Shuttle
The Space Shuttle was a manned orbital rocket and spacecraft system operated by NASA on 135 missions from 1981 to 2011. The system combined rocket launch, orbital spacecraft, and re-entry spaceplane with modular add-ons...

, while far faster than the X-43 or X-15, is not regarded as an aircraft during ascent as it is carried ballistically
Ballistics
Ballistics is the science of mechanics that deals with the flight, behavior, and effects of projectiles, especially bullets, gravity bombs, rockets, or the like; the science or art of designing and accelerating projectiles so as to achieve a desired performance.A ballistic body is a body which is...

 by rocket thrust, rather than the air. During re-entry it is classed (like a glider) as an unpowered
Gliding
Gliding is a recreational activity and competitive air sport in which pilots fly unpowered aircraft known as gliders or sailplanes using naturally occurring currents of rising air in the atmosphere to remain airborne. The word soaring is also used for the sport.Gliding as a sport began in the 1920s...

 aircraft.

Aerodynamics



Because of the way they work, the typical exhaust speed of jet engines is transonic or faster, therefore most jet aircraft need to fly at high speeds, either supersonic
Supersonic
Supersonic speed is a rate of travel of an object that exceeds the speed of sound . For objects traveling in dry air of a temperature of 20 °C this speed is approximately 343 m/s, 1,125 ft/s, 768 mph or 1,235 km/h. Speeds greater than five times the speed of sound are often...

 or speeds just below the speed of sound ("transonic
Transonic
Transonic speed is an aeronautics term referring to the condition of flight in which a range of velocities of airflow exist surrounding and flowing past an air vehicle or an airfoil that are concurrently below, at, and above the speed of sound in the range of Mach 0.8 to 1.2, i.e. 600–900 mph...

") so as to achieve efficient flight. Aerodynamics is therefore an important consideration.

Jet aircraft are usually designed using the Whitcomb area rule, which says that the cross-section of the aircraft at any point must be approximately the same as the Sears-Haack body
Sears-Haack body
The Sears–Haack body is the aerodynamic body shape with the lowest theoretical wave drag. Aircraft designed to operate at high subsonic or supersonic speeds have their cross-sectional areas designed to match as closely as possible the proportions of Sears-Haack body.By Whitcomb's area rule, the...

. This minimises the production of shockwaves which would waste energy.

Jet engines


Jet engines come in several main types:
  • turbojet
  • turbofan
    Turbofan
    The turbofan is a type of airbreathing jet engine that is widely used for aircraft propulsion. A turbofan combines two types of engines, the turbo portion which is a conventional gas turbine engine, and the fan, a propeller-like ducted fan...

     (which come in two main forms low bypass turbofan and high bypass turbofan)
  • rocket
    Rocket
    A rocket is a missile, spacecraft, aircraft or other vehicle which obtains thrust from a rocket engine. In all rockets, the exhaust is formed entirely from propellants carried within the rocket before use. Rocket engines work by action and reaction...



The types are used for different aircraft. Turbojets are seldom used, but was used on Concorde; it has a high exhaust speed and low frontal cross-section, and so is best suited to high-speed flight. Low bypass turbofans have a lower exhaust speed than turbojets and are used for transonic and low supersonic speeds. High bypass turbofans are used for subsonic aircraft and are quite efficient and are widely used for airliners.

Rockets have extremely fast exhaust speeds and are mainly used when high speeds or extremely high altitudes are needed.

See also

  • Jumbo jet
  • Jet airliner
    Jet airliner
    A jet airliner is an airliner that is powered by jet engines. This term is sometimes contracted to jetliner or jet.In contrast to today's relatively fuel-efficient, turbofan-powered air travel, first generation jet airliner travel was noisy and fuel inefficient...

  • Commercial aviation
    Commercial aviation
    Commercial aviation is the part of civil aviation that involves operating aircraft for hire to transport passengers or cargo...

  • Contrail
    Contrail
    Contrails or vapour trails are artificial clouds that are the visible trails of condensed water vapour made by the exhaust of aircraft engines...

  • Range (aircraft)
    Range (aircraft)
    The maximal total range is the distance an aircraft can fly between takeoff and landing, as limited by fuel capacity in powered aircraft, or cross-country speed and environmental conditions in unpowered aircraft....

     the range can be calculated using the Breguet range equation.
  • Very light jet
    Very Light Jet
    A very light jet, entry-level jet or personal jet, previously known as a microjet, is a category of small jet aircraft approved for single-pilot operation, seating 4-8 people, with a maximum take-off weight of under...

  • List of jet aircraft of World War II

External links