Title: Boeing 727 Content:  The Boeing 727 is a jet airliner. It is made by Boeing Commercial Airplanes. It can carry 149 to 189 passengers. It can fly for . The Boeing 727 was made to fly short distances. It can also take off from short runways at smaller airports. It has three Pratt & Whitney JT8D engines. One engine is at the back, and the other two are on the sides of the plane. The 727 is the only plane made by Boeing which has three engines. The Boeing 727 was made after the Boeing 707. The 727 and the 707 have some similar features. The 727-100 first flew in February 1963. The first airline to use it was Eastern Air Lines. The 727-200, a longer version of the 727, first flew in July 1967. It was first used by Northeast Airlines in December 1967. The 727 was made during the 1970s. The last 727 was made in 1984. In July 2011, 23 727-100s and 227 727-200s were being used by airlines. The 727 is a very noisy aircraft, so some 727s have been given hush kits to make them quieter. ==Development== The Boeing 727 was made to fly from small cities which had airports with shorter runways. It also carried fewer passengers. United Airlines wanted a plane with four engines so that it could fly to airports which were at high altitude. An example of an airport like this is Stapleton International Airport in Denver, Colorado. American Airlines wanted a plane with two engines. Eastern Airways wanted a plane with three engines so that it could fly to the Caribbean. The airlines decided to ask for a trijet, which is a plane with three engines. thumb|left|upright|Production of the 727 In 1959, Lord Douglas said that Boeing and de Havilland Aircraft Company should work together to make trijets. Boeing made the 727 and de Havilland made the D.H.121 Trident.Connors, p. 355. The two planes were quite similar, but the 727 was a bit bigger. Boeing wanted to use Allison AR963 turbofan engines for the 727. The de Havilland plane also used these engines. Boeing and de Havilland sent engineers to look at each other's designs. However, Boeing decided not to work together with de Havilland and changed the engine.Connors, p. 357. In 1960, Pratt & Whitney wanted to sell its new JT8D turbofan engine design.Connors, pp. 348–349. United and Eastern were interested in this engine,Connors, p. 350. so Pratt & Whitney decided to keep designing it. Eddie Rickenbacker, from Eastern, told Boeing that the airline wanted JT8D engines for its 727s. At first, Boeing did not want to use the JT8D for the 727, but it eventually decided to use the JT8D.Connors, p. 352. The 727 has special parts on its wings which help it to make more lift.Eden, Paul. (Ed). Civil Aircraft Today. 2008: Amber Books, pp. 72–3. This means that it can take off from shorter runways than most other jets. Later, some longer 727s were made to carry more passengers.Eden 2008, pp. 74–5. They replaced other jet airliners like the Boeing 707 and Douglas DC-8. They also replaced propeller planes like the DC-4, DC-6, DC-7 and the Lockheed Constellation. Boeing stopped making the 727 in 1984. 1,832 were made. 1,831 of these were given to an airline. ==Design== thumb|Boeing 727-200 of Air Algérie in September 1981 The 727 was meant for small airports. This meant that it would have to do without some things like stairs. Boeing built airstairs into the 727. At first, the airstairs could be opened while the plane was flying. However, D. B. Cooper, who was a hijacker, jumped out of a 727. This happened while it was flying over the Pacific Northwest. Boeing then changed the design so that the airstairs could not be opened while the plane was flying. The 727 also had an auxiliary power unit (APU). This meant that the 727 could run its systems without any power from the ground. The APU is near the undercarriage. This is quite unusual. thumb|left|Lloyd Aéreo Boliviano 727-200 at Jorge Wilsterman Airport. The rear air stairs are visible at the 727's tail. One thing which allowed the 727 to land on short runways was the design of its wings. The 727 had no engines on its wings, so flaps could be used on the full wing. There were also some other things which made more lift. Together, these things make a lift coefficient of 3.0.Case Study in Aircraft Design; the Boeing 727, American Institute of Aeronautics and Astronautics Professional Study Series, September 1978. ===Noise=== The 727 is one of the noisiest airliners. The 727's JT8D engines are low-bypass. This makes them much noisier than high-bypass engines. Boeing thought about giving the 727 quieter engines. They said that the JT8D-200 engine could be used. All 727s being used today need to be given a hush kit. A hush kit is something which makes a jet engine quieter. FedEx makes one of these kits. Over 60 companies have bought this. Winglets have also been made for the 727 by different companies. 727s (including 727s which have a hush kit) are banned from some airports in Australia because of how much noise they make. ==History== The 727 could fly to different countries as well as to places in the same country. It is useful in airports where the runway is made of gravel. Since the engines are so high up, there is not much risk that they will be damaged by things on the ground. thumb|left|Cockpit of a flight simulator Boeing 727 at the Pan Am International Flight Academy thumb|N281FE, a FedEX 727-233, leaving Portland International Airport in Oregon The 727 was also used by the military. Since the airstairs could be opened while the plane was flying, the Central Intelligence Agency used them to put agents and supplies into Vietnam. The Boeing C-22 was used by the Air National Guard and National Guard Bureau to airlift people. Three C-22B's were used. All of them belonged to the 201st Airlift Squadron, District of Columbia Air National Guard. thumb|A FedEx 727 at Portland International Jetport in Maine with cargo doors open The replacement for the 727 was the Boeing 757. However, the 757 is much bigger than the 727. Because of this, some airlines replaced the 727 with the 737-800 or the Airbus A320. ==Different types of Boeing 727