Marty Tichnell: Exactly it wouldn't be worthwile and the loss of thrust reduces speed and you can't as far
Kaley Lappas: It's range would shrink, though the aircraft's endurance (number of hours it can remain in the air) would probably increase somewhat... more so with a jet aircraft than a prop driven aircraft due to prop drag.
Rufus Plough: Small aircraft have air cooled engines because they are lighter and less complex then water cooled engines. There is however a diesel engine that is on the market that does have water cooling. Not sure why it is water cooled other then its makes for better engine temperature control. The most engine cooling required is at low altitudes and high power setting when taking off and climbing to altitude so the cold of high altitudes is not available for cooling.
Dewey Heersink: it will decrease the thrust.the A/C will continue to drop its height.so altitude of the A/C will vary time to time.it may cause mid air collis! ion.there are so many other reasons also.i am an AME student....Show more
Matt Tiry: believe it or not folks in some cases it will. specifically, we were doing proving runs to acquire a 135 ops spec for international operations in a gulfstream III. with the feds on board, we had to show the fuel used from the equal time point during a flight from oakland to honolulu should one engine flame out at precisely that point. after drift down to an altitude of 23,000 ft. it showed we'd have more fuel on board in HNL than had both engines kept running. of course this flight had been planned at mach .80 and not at the much slower LRC setting but still, the range was increased by losing one engine.after we went through this drill, i turned to the fed sitting in the jumpseat, a longtime friend, and said "tommy, don't you dare mention this to my boss. he'll have me stop cocking an engine half way through every flight we make if he thinks it'll costs him less fuel". loladditionally! , the 727 that i flew had the "valsan" engine mod which replac! ed the two outboard engines with the newer more efficient and powerfull pratt JT8D-219 engines. the original -7A pratt stayed in the center and a hush kit was installed on it. this made the aircraft conform to stage three noise limitations. once we were in cruise flight, we would idle number two, efectively shutting it down except we still had it's alternator and hydraulic pump, and push up 1 and 3. the result was a lower fuel burn for an equal amount of total thrust had we kept the throttles matched. that center engine stayed at idle until we began the approach....Show more
Barrett Zheng: There are a lot of variables involved. It depends on the weight to thrust ratio of the aircraft. Modern jets must be able to carry out their mission with one or more engines out and they have to prove it. See the link on the 777. As solely the means to increase range it is not a good idea, it is easier to add more fuel.
Cortez Badolato: That's the reason jet aircraft fly up ar! ound 30,000 ft plus, because of greater efficiency from the engines, the throttles are pulled back to cruising,Maritime patrol aircraft often shut down 1 or 2 engines so they can remain on patrol longer, not to just save on fuel.So the answer to your question would be yes, but world wide civilian airline regulations do not allow commercial aircraft to do this for safety reasons....Show more
Darnell Cutliff: For 747s that make trans-pacific flights, losing an engine or shutting an engine down would require an added amount of power that would make it so it couldn't continue to its destination
Dannie Briseno: The drag is there anyway, but the loss of thrust and the asymmetric thrust would result in more fuel consumption from the other engines. Think about it - you can't get that kinetic energy without using the potential energy in the fuel, and the most efficient way to convert that potential energy to kinetic energy is by using the system as designed. You can't ge! t something for nothing. If you save it in one place, you simply have t! o spend it someplace else, or you won't maintain altitude and airspeed. And if you spend it someplace else, it will be so inefficient that you will end up spending more anyway. The only way I know of to save fuel in this manner is to shut one or two engines down while taxiing in. This is pretty insignificant, but it's not zero. I assume you were ignoring safety issues, which would never allow this anyway.ADDED: Mr ph bill -I think the Collier Trophy was awarded for the design of the aircraft, not for this one feature, which I must admit I do not understand. Let me put it this way - If it saves fuel to shut one engine down, then it also must save some fuel to just pull it to flight idle. If flight idle is set so high that by pulling one engine back, the aircraft can maintain altitude and airspeed, then how does the pilot ever descend? Speed brakes? Is there that much difference between flight idle on one engine and flight idle on two? Is flight idle set high - essentially th! e same as cruise for icing concerns? I must be missing something.I think that if they do run on one engine, they do not simply shut the other engine down. There has to be some re-configuration, or fuel control change, or the physics does not add up.ADDED(2): Mr John B - I must respectfully disagree. You are comparing an extended flight at .8M and constant altitude with a slow descent at max range throttle setting. Then you apparently extrapolated these results through landing, and concluded that you would have extended range. While I admit you got better range, that's not what we engineers would call a valid test. You cannot get something for nothing. Unless your shutdown engine had a fuel leak or a really unusual burner efficiency figure, you would have used as much or more fuel if you had maintained altitude and .8M with the single engine. Since the descent is to some extent controlled by engine thrust, the test could not be done properly by both aircraft descending, eith! er. It's apples and pomegranates. Please understand, I'm glad you did t! he test, but I would not be able to justify it technically as proof of anything. In fact, your need to convert to a slow descent sort of proves the point I was trying to make....Show more
Majorie Chester: yes but if your prop will not feather its not good to windwill without oil .the navy would do this with the p3 orion but I would never shutoff an eng in flight just to save gas
Donella Vasta: IF it was worthwhile the airlines would have been doing it for years. also in terms of air safety, part of the reason the airlines use 4 engined aircraft is that the safety restrictions are different, meaning they can take a mroe direct route without being as close to alternate airports
Lu Snide: No. Transport category aircraft operate most efficiently at a fairly high Mach number, and shutting down an engine will probably reduce the speed to a less efficient value.
Annabell Bevier: Actually a flight profile was developed for the Boeing 777 shutting down one ! engine in cruise to extend its range because of the profile success the 777 was approved for ETOPS twin engine operations. Several Boeing aircraft have been approved for these operations in this manner. The Collier award was presented for this achievement....Show more
