Sources
Help build the largest human-edited directory on the web.
Submit a site - Become an editor
Wikipedia. Licensed under the GNU Free Documentation License.
Are you an expert in this subject? Join the discussion and share your knowledge at Wikipedia.org.
Jet aircraft
From Wikipedia, the free encyclopedia
 |
This article may require cleanup to meet Wikipedia's quality standards. Please improve this article if you can. (August 2006) |
Jet aircraft are aircraft with jet engines. Unlike propeller-powered aircraft, jet aircraft normally fly at altitudes as high as 10,000 to 15,000 meters, about 33,000 to 49,000 feet (14,900 m). At these altitudes, jet engines can achieve maximum efficiency over long distances. The engines in propeller powered aircraft achieve their maximum efficiency at much lower altitudes.
Contents |
The first aircraft to incorporate the principles of the jet engine was the Coanda-1910, piloted by its Romanian inventor Henri Coandă in 1910. The engine of this aircraft, unlike the modern jet engine, used a piston engine rather than a turbine to drive its compressor. The aircraft crashed during its first and only demonstration but remained intact.
The first true turbine-equipped jetplane was the Heinkel He 178 (Germany), piloted by Erich Warsitz in 1939 (August 27, 1939).
The British flew their Gloster E.28/39 powered by Sir Frank Whittle's turbojet on May 15, 1941, with Flt Lt PG Sayer as pilot. The United States, upon learning of the British work, produced the Bell XP-59, with a version of the Whittle engine built by General Electric which flew on September 12, 1942 with Col L. Craigie as pilot.
The first operational jet fighter was the Messerschmitt Me 262, piloted by Fritz Wendel. It was the fastest conventional aircraft of World War II - only the rocket-powered Messerschmitt Me 163 Komet was faster. Mass production started in 1944, too late for a decisive impact. About the same time, the United Kingdom's Gloster Meteor made up the first operational jet fighter squadron in 1944. It was used to defend the UK against the V1 flying bomb and in ground-attack operations over Europe towards the end of the war. The Imperial Japanese Navy also developed jet aircraft in 1945, including the Nakajima J9Y Kikka, partially inspired by German designs.
On November 8, 1950, during the Korean War, United States Air Force Lt. Russell J. Brown, flying in an F-80, intercepted two North Korean MiG-15s near the Yalu River and shot them down in the first jet-to-jet dogfight in history according to USAF sources. Soviet Sources say a Mig 15 shot down a P 80.
BOAC operated the first commercial jet service, from London to Johannesburg, in 1952 with the de Havilland Comet jetliner.
The fastest military jet plane was the SR-71 Blackbird at Mach 3.2.
The fastest commercial jet plane was the Tupolev Tu-144 at Mach 2.35.
Modern jets generally cruise at speeds of 0.75 to 0.85 Mach, or 75 to 85% of the speed of sound (420 to 580 mph/ 680-900 km/h). The speed of sound is a function of air temperature and pressure, and therefore the speed of a jet is not constant in terms of miles per hour, but varies with atmospheric conditions. NASA and the FAA have recently been promoting Very Light Jets, small general aviation aircraft seating 4 to 8.
Most people use the term 'jet aircraft' to denote gas turbine based airbreathing jet engines, however, both rockets and scramjets are both also propelled by jets.
The fastest airbreathing jet aircraft is the unmanned X-43 scramjet at around Mach 9-10.
The fastest manned (rocket) aircraft would be the X-15 at Mach 6.85.
The Space Shuttle, while far faster than the X-43 or X-15, is not regarded as an aircraft during ascent, and is unpowered when flying as an aircraft during reentry and landing. It is therefore not considered a jet aircraft at either time.