History Trijet

the mcdonnell douglas md-11, stretched , redesigned successor dc-10, recent trijet design produced commercial aviation service.



rossiya tupolev tu-154 trijet landing



the dassault falcon 900 business jet

the first trijet design fly tupolev tu-73 bomber prototype, first flown in 1947. first commercial trijets hawker siddeley trident (1962) , boeing 727 (1963). both compromises meet airline requirements; in case of trident, meet bea s changing needs, while 727 had acceptable 3 different airlines. although collaboration between manufacturers considered, did not come about.

early american twinjet designs limited faa s 60-minute rule, whereby flight path of twin-engine jetliners restricted within 60 minutes flying time suitable airport, in case of engine failure. in 1964, rule lifted trijet designs, had greater safety margin.

for second-generation jet airliners, innovations of high-bypass turbofan greater efficiency , reduced noise, , wide-body (twin-aisle) greater passenger/cargo capacity, trijet design seen optimal configuration medium wide-body jet airliner, sitting in terms of size, range, , cost between quadjets (four-engine aircraft) , twinjets, , led flurry of trijet designs. four-engine boeing 747 popular transoceanic flights due long-range , large size, expensive , not routes able fill seating capacity, while original models of airbus a300 twinjet limited short- medium-range distances. trijet designs such dc-10 , l-1011 tristar represented best compromise medium- long-range , medium size airlines sought domestic , transatlantic routes. result of these trijet wide-bodies, popularity of boeing 727, in heyday of 1980s trijets made majority of such jet airlines.

however, improvements in engine reliability , subsequent relaxation in airline safety rules made trijet obsolete normal passenger services, , no manufacturer produces three-engine airliners. 1985 2003 number of such planes in service had sunk 1488 602. number of twinjets had more quadrupled in same period. both lockheed , mcdonnell douglas financially weakened competing in trijet widebody market, led lockheed ending production of l-1011 tristar in 1984 after producing half units needed break even, while dc-10 sales slowed. in 1980s boeing 727 discontinued, s-duct central engine bay require prohibitively expensive redesign accommodate quieter high-bypass turbofans, , supplanted twinjets narrow-body market; airbus a320, , boeing 757 , updated classic variants of 737.

during 1980s, mcdonnell douglas aircraft manufacturer continue development of trijet design update dc-10, md-11, held range , payload advantage on closest medium wide-body competitors twinjets, in-production boeing 767 , upcoming airbus a330. mcdonnell douglas had planned new series of dc-10 family trijets called md-xx, lengthened versions of md-11. md-xx long range have been capable of travelling distances 8,320 nautical miles , had wingspan of 213 feet. project cancelled in 1996, 1 year before mcdonnell douglas acquired boeing. boeing ended production of md-11 after filling remaining customer orders since md-11 have competed boeing s own offerings. study remove md-11 s tail-mounted engine (which have made twinjet) never came fruition, furthermore md-11 had nothing in common in terms of design or type rating other boeing jet airliners. in contrast mcdonnell douglas sticking existing trijet configuration, airbus (which never produced trijet aircraft) , boeing worked on new widebody twinjet designs become airbus a330 , boeing 777, respectively. md-11 s long range advantage brief nullified airbus a330 s four-engine derivative, airbus a340, , extended-range boeing 767-300er , boeing 777-200er.

current status

modern engines have extremely low failure rates , increased power output. makes twinjets more suitable long-haul overwater operation, resulting in eased etops restrictions; modern wide-body twin-engine jets have etops 180 or (in case of boeing 777 , 787) etops 330 rating. such, having more 2 engines no longer considered necessary, except large aircraft such boeing 747 , airbus a380 (over 400 seats in mixed-class configuration), or flights through southern hemisphere, , australia (which has not yet adopted etops 330 standard), direct route on antarctica.

today, both narrow-body , wide-body trijet production has ceased commercial aircraft, being replaced twinjets. of 2016, dassault falcon 7x, dassault falcon 8x, , dassault falcon 900 business jets, of feature s-ducts, trijets in production. old trijets, such boeing 727, tupolev tu-154, mcdonnell douglas dc-10, , md-11, have found second careers cargo aircraft, limited charter, governmental, , military service. currently, used trijets dc-10 , md-11, operated ups airlines , fedex express cargo planes.

future of trijets

airbus filed patent in 2008 new, twin-tail trijet design, unknown if ever developed or produced. proposed boeing x-48 blended wing body design has 3 engines. proposed supersonic aircraft designs feature trijet configuration, such lockheed s n+2 design study , aerion s as2 supersonic business jet. latter taking orders , wooden mockup has been constructed.