Jamesbuk From United Kingdom, joined May 2005, 3968 posts, RR: 4
Reply 1, posted (8 years 9 months 22 hours ago) and read 11617 times:
Nope, aircraft are a hell of alot more efficient now with 2 engines, look at the 777 etc to see this, they have longer range also. Never is a strong word but im certain we'll never see another 3 engine passenger commercial jet. Privates not so surre, may see a few.
You cant have your cake and eat it... What the hells the point in having it then!!!
LuvAir From Germany, joined Oct 2006, 22 posts, RR: 0
Reply 5, posted (8 years 9 months 22 hours ago) and read 11513 times:
As I understand it the main reason for 3-engined jets "back in the days" was the capability to fly longer routes over water.
Since for example the 777 was granted 180 min ETOPS on initial certification I don't see a reason for future twins from the large manufacturers not to be certified for extended routes over water from the beginning.
Lightsaber From United States of America, joined Jan 2005, 14284 posts, RR: 100
Reply 9, posted (8 years 9 months 19 hours ago) and read 11148 times:
Quoting Flyf15 (Reply 7): The Blended Wing Body is proposed to have three 777 class engines. But, thats a long way off (if it ever happens).
The 550 to 800 seat BWB's are in a category where 3 engines actually make the most sense. What I don't understand is the 215 BWB discussed in the previous days with 3... There it makes zero sense. Why would you replace a 787 with an aircraft with higher MX costs? The cost of an engine overhaul can be roughly estimated to be identical *per engine* for that small of a size difference. Ok, if you're talking large fans, there is a diameter above which 3 engines can be more economical than two (assumption: 3 engines at a smaller diameter). However that diameter grows in fits and starts every couple of years.
There is a "step increase" for engine production and MX where above a certain diameter costs just shoot up. But this diameter goes up in fits and starts. The diameter I was taught is already out of date...
In rough terms, a 3 engine plane costs about $250,000+ more a year to operate than a 2 engine equivalent. However, the GE-90 has engines of diameter greater than the "step function increase" I talk about. Even then, its still not a large enough diameter to justify 3 engines on the 777... What is the point? Currently 150K is my best estimate. But maybe someone has figured out a trick to move the thrust limit up further that I do not know about...
Starlionblue From Greenland, joined Feb 2004, 17351 posts, RR: 66
Reply 11, posted (8 years 9 months 18 hours ago) and read 11007 times:
Quoting LuvAir (Reply 5): As I understand it the main reason for 3-engined jets "back in the days" was the capability to fly longer routes over water.
Another reason often touted is that a triplet allowed the DC-10 and L-1011 to fly transcon from LGAs short runways (a requirement from the airlines). A quad would have required too much wingspan to fit at the gates.
The tail engine is a big pain in the ass (haha) for aerodynamic and structural reasons, not to mention maintenance. If we see a triplet again in a commercial jet, it will be, as stated above, on a BWB or similar.
"There are no stupid questions, but there are a lot of inquisitive idiots."
Does anyone know what fraction of their sales are the two engine Falcon 2000?
Quoting Starlionblue (Reply 11): The tail engine is a big pain in the ass (haha) for aerodynamic and structural reasons, not to mention maintenance. If we see a triplet again in a commercial jet, it will be, as stated above, on a BWB or similar.
Quoting Alessandro (Reply 13): I´m personally hoping for a 5-engine jet, but that even more distant...
Propulsion From United Kingdom, joined Jun 2004, 294 posts, RR: 3
Reply 16, posted (8 years 9 months 16 hours ago) and read 10724 times:
NO. The mighty Boeing 777 has assured us of that.
Unfortunately you should enjoy the tri-jets while you can. They will almost certainly be a thing of the past. Something in history that will not be experienced again. How sad, especially since MD-11's are so beautiful.
A bus is a vehicle that runs twice as fast when you are after it as when you are in it.
DC10extender From United States of America, joined Nov 2006, 617 posts, RR: 0
Reply 17, posted (8 years 9 months 16 hours ago) and read 10712 times:
I don't think that they will make a 3 engine jet ever again, and that saddens me. This January, NW will retire their DC-10's and become the last major US airline to do so. I just wish the MD-11's sold more and more were being used in the U.S. I also think that instead of sending them to the Mojave, they should give me a DC-10.
Did you ever read on your birth certificate that life is fair? Thats cause its not there.
N231YE From , joined Dec 1969, posts, RR:
Reply 24, posted (8 years 9 months 13 hours ago) and read 10459 times:
If I recall, Eastern Airlines requested that the Boeing 727 have two engines for efficiency. However, United wanted it to have 4, to enable it to operate out of high-altitude DEN. So Boeing did a compromise, and came up with a three-engined jet.
: It is really a mess that Boeing killed the MD11x-Program shortly after take-over of MDD. That MD11-stretch version would have been a huge success and
: I feel your pain! But thats a given from my username Because Airbus and Boeing have an oligopoly on the industry we will probably never see another t
: Doesn't BA fly 3-engined jets from time to time?
: I wish... The last DC10-30 was sold to Centurion Air Cargo in 2002. The last Tristar 500 was retired in 1999. It has since been scrapped.
: Excellent. Saving fuel from LAX to the U.K. I hope to be recalled to fly on the three-holers. I just hope the Tristar is still around when that time
: Not sure the FAA would approve of them doing it again Especially if they do it the way they did it last year (?) in a 744.
: That's not really the reason. If a trijet was a feasible solution, it would be implemented. Flying on three doesn't really save fuel. What they did w
: I have a question, why didn't Airbus make the A340 a trijet back whennit was designed? That way they could offer a plane that wasn'tnrestricted by ETO
: So did the 727. The 757 became what was supposed to be the 727-300. One version of the 727-300 was supposed to be a really long 727, while the other
: To resume and make it simple, there are 2 main reasons why there won't be any 3 engined jets for a while: 1. Maintenance costs 2. Nowadays with GE90s
: You're thinking of the 7J7, which was supposed to be the 150 seat successor to the 727. It was to be powered by two rear-mounted General Electric GE-
: Yeah the 7J7, I was thinking it was an updated 727 since it looks a lot like one with just two engines. On a side note, weren't there other 7()7 aircr
: I think it would be neat to see another 717-sized aircraft with 3 engines. Every 9 out of 10 aircraft anymore have wing-mounted engines. I am a big fa