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Trijet For Y3?  
User currently offlineDEVILFISH From Philippines, joined Jan 2006, 4775 posts, RR: 1
Posted (7 years 2 months 3 weeks 5 days 7 hours ago) and read 3999 times:

Here's a question totally from out of left field. Is there a possibility of the 777/747 replacement being a trijet? What would be its economic advantages over a four-engined 748 replacement - given the well-worn arguments of structural and maintenance challenges for the No. 2 engine? Considering the slow sales of pax 748 and engine makers' reluctance to develop bigger and evermore powerful engines to put on the next generation planes, would it be easier for them to come up with a comparatively less complicated variant that would satisfy the OEI requirements for a trijet and the high efficiencies and capacities demanded by the airlines? I would imagine a bigger, all-composite fuselage like the 787, or farther out, something like the X-48B that Boeing is testing.

http://www.flightglobal.com/articles...nx-variant-may-yet-power-a350.html

Snecma Tests Future Engine Concept (by Lumberton Apr 27 2007 in Tech Ops)

http://seattletimes.nwsource.com/htm...echnology/2003681476_boeing26.html

http://www.boeing.com/news/releases/2006/q4/061027b_pr.html

[Edited 2007-04-29 16:52:37]


"Everyone is entitled to my opinion." - Garfield
44 replies: All unread, showing first 25:
 
User currently offlineStarlionblue From Greenland, joined Feb 2004, 16991 posts, RR: 67
Reply 1, posted (7 years 2 months 3 weeks 5 days 1 hour ago) and read 3933 times:

Quoting DEVILFISH (Thread starter):
Here's a question totally from out of left field. Is there a possibility of the 777/747 replacement being a trijet?

Interesting idea but small likelihood

Quoting DEVILFISH (Thread starter):
What would be its economic advantages over a four-engined 748 replacement - given the well-worn arguments of structural and maintenance challenges for the No. 2 engine?

One less engine=good. However, I think you answered your own question. Triplets are just plain costly. A quad is probably a better idea.

Pity though. I like triplets.



"There are no stupid questions, but there are a lot of inquisitive idiots."
User currently offlineSpeedracer1407 From United States of America, joined Dec 2004, 333 posts, RR: 0
Reply 2, posted (7 years 2 months 3 weeks 4 days 16 hours ago) and read 3836 times:

Quoting Starlionblue (Reply 1):
Triplets are just plain costly. A quad is probably a better idea.

Pity though. I like triplets.

I'm sure the majority of A.net members wish someone would put a new triplet into service, including myself. So, inspired by nothing other than wishful thinking, I wonder if a somewhat near-term (next 5-10 years or so) trijet Y3 design might have just a few advantages that may (or indeed may not) offset the inherent costliness of the type.

Firsly, greater use of composites in a trijet design may close the gap in wieght between it and twin/quad designes.

Secondly, next generation engines (GEnx) are pretty much ready to go in the next year or so, but aren't available in the thrust class necessary for a twin of 777-748 size. Seems to me like developting a 100Klb + NG engine will be very expensive, considering the already high price and and advanced techonolgies used in the GE90, so perhaps development costs saved by installing three existing, highly efficient engines in the 60-80Klb thrust class on a Y3 trijet might offset some of the costs involved in designing and maintaining that #2 engine.

Probably not though, but I wish it were that simple.



Dassault Mercure: the plane that has Boeing and Airbus shaking in their boots.
User currently offlineBrenintw From Taiwan, joined Jul 2006, 1607 posts, RR: 1
Reply 3, posted (7 years 2 months 3 weeks 4 days 14 hours ago) and read 3821 times:

Quoting Speedracer1407 (Reply 2):
Secondly, next generation engines (GEnx) are pretty much ready to go in the next year

What I've written below are my thoughts as an outsider ...

Looking at the size of the engines currently slung under the wings of the 773ER -- and knowing that they're smaller in diameter than those on the 772LR etc -- I can't imagine there would be any feasible way of plugging one of those into the tail of an aircraft. A lot of the thrust of the current generation engines comes from those fans chewing up enormous amounts of air ... a smaller fan diameter would result in lower thrust.

Furthermore, the sheer weight of modern high-bypass engines would make CG-management a real bear.



I'm tired of the A vs. B sniping. Neither make planes that shed wings randomly!
User currently online747400sp From United States of America, joined Aug 2003, 3480 posts, RR: 2
Reply 4, posted (7 years 2 months 3 weeks 3 days 23 hours ago) and read 3689 times:

It could end up being like the 763-246C, with four engines and an extremely wide body (three - aisle 12 or 13 abreast in economy cabin), on one deck. But instead of it looking like a over size 777( like the 763-246C did) it will look like a oversize 787.

User currently offlineSEPilot From United States of America, joined Dec 2006, 6817 posts, RR: 46
Reply 5, posted (7 years 2 months 3 weeks 3 days 5 hours ago) and read 3617 times:

Quoting Brenintw (Reply 3):
Looking at the size of the engines currently slung under the wings of the 773ER -- and knowing that they're smaller in diameter than those on the 772LR etc -- I can't imagine there would be any feasible way of plugging one of those into the tail of an aircraft. A lot of the thrust of the current generation engines comes from those fans chewing up enormous amounts of air ... a smaller fan diameter would result in lower thrust.

Furthermore, the sheer weight of modern high-bypass engines would make CG-management a real bear.

 checkmark 
I was going to say almost exactly the same thing; you beat me to it.



The problem with making things foolproof is that fools are so doggone ingenious...Dan Keebler
User currently offlineLemurs From United States of America, joined Mar 2005, 1439 posts, RR: 4
Reply 6, posted (7 years 2 months 3 weeks 3 days 4 hours ago) and read 3604 times:

Quoting Brenintw (Reply 3):
A lot of the thrust of the current generation engines comes from those fans chewing up enormous amounts of air ... a smaller fan diameter would result in lower thrust.

Furthermore, the sheer weight of modern high-bypass engines would make CG-management a real bear.

GTF could change these equations somewhat. Smaller turbomachinery to drive larger fans...more efficient fan design enabled by more optimally controlable rotational speeds, etc. In theory, it could allow for an upgrade in thrust in roughly the same size/weight package, or the same thurst in a smaller, lighter one...

All of this depends on how well the Y1 engine programs turn out of course, and what kind of operational obstacles they hit with engine design and maintainance...but it's easy to see why Boeing would want to make sure Y3 is behind Y1. They're not going to want to go for a tri/quad if they can help it at all, in any fashion...and that means they need to make some more big breakthroughs in design and materials to get up to 748 sizes in a twin...



There are 10 kinds of people in the world; those who understand binary, and those that don't.
User currently offlineSEPilot From United States of America, joined Dec 2006, 6817 posts, RR: 46
Reply 7, posted (7 years 2 months 3 weeks 3 days 2 hours ago) and read 3580 times:

Quoting Lemurs (Reply 6):
GTF could change these equations somewhat. Smaller turbomachinery to drive larger fans...more efficient fan design enabled by more optimally controlable rotational speeds, etc. In theory, it could allow for an upgrade in thrust in roughly the same size/weight package, or the same thurst in a smaller, lighter one...

But that does not change fan diameter, which would still remain too large to use on the tail.



The problem with making things foolproof is that fools are so doggone ingenious...Dan Keebler
User currently offlineTrijetsRMissed From United States of America, joined Oct 2006, 2323 posts, RR: 7
Reply 8, posted (7 years 2 months 3 weeks 3 days ago) and read 3560 times:

I would say this would be possible if the MD line in Long Beach was not discontinued when Boeing took over Douglas, and in short, if it really was a "merger." All hopes of a future tri-jet widebody died with McDonnell Douglas.

Boeing on the other hand, has not designed a tri-jet in over 45 years. The 727 narrow-body design will not be brought back and it is highly unlikely Boeing will attempt to engineer their first tri-jet widebody at this point. There is a better chance of us seeing a modernized "L-1011-1000."  sarcastic 



There's nothing quite like a tri-jet.
User currently offlineMDorBust From , joined Dec 1969, posts, RR:
Reply 9, posted (7 years 2 months 3 weeks 3 days ago) and read 3554 times:

Quoting SEPilot (Reply 7):
But that does not change fan diameter, which would still remain too large to use on the tail.

Unless you embeded the engine in the rear empenage of the fuselage aft of the pressure bulkhead. As long as the fan diameter is smaller than the diameter of the fuselage you could make it fit.

Instead of a single S-duct like the 727 and L-1011 you could put Harrier style ducts on to split the size of the intake between the two sides of the aircraft.

Of course, you would have to move the wing further to the rear to compensate for the shift in COG.

Of course the big question remains... WHY?

Hasn't the low sales of the A380 and 747-8 taught us about the direction in aircraft size?


User currently offlineStarlionblue From Greenland, joined Feb 2004, 16991 posts, RR: 67
Reply 10, posted (7 years 2 months 3 weeks 2 days 20 hours ago) and read 3531 times:

Quoting Speedracer1407 (Reply 2):
Firsly, greater use of composites in a trijet design may close the gap in wieght between it and twin/quad designes.

Sure, but wing mounting is still cheaper. Also, wing mounting offsets wing bending moment, allowing a lighter wing.

Quoting Brenintw (Reply 3):
Looking at the size of the engines currently slung under the wings of the 773ER -- and knowing that they're smaller in diameter than those on the 772LR etc -- I can't imagine there would be any feasible way of plugging one of those into the tail of an aircraft. A lot of the thrust of the current generation engines comes from those fans chewing up enormous amounts of air ... a smaller fan diameter would result in lower thrust.

And that's one of the things that killed McD. The banjo fitting for the MD-11 was very costly to engineer. Scaling the banjo further for the MD-XX (trijet variant) would have been prohibitibe.

Quoting 747400sp (Reply 4):
It could end up being like the 763-246C, with four engines and an extremely wide body (three - aisle 12 or 13 abreast in economy cabin), on one deck

As I recall, you run into structural issues with such a shape. Meaning more weight. Pity. Would be cool.

Quoting MDorBust (Reply 9):

Unless you embeded the engine in the rear empenage of the fuselage aft of the pressure bulkhead. As long as the fan diameter is smaller than the diameter of the fuselage you could make it fit.

Instead of a single S-duct like the 727 and L-1011 you could put Harrier style ducts on to split the size of the intake between the two sides of the aircraft.

Neat idea. I like it. Doesn't really resolve some of the other problems.


Not trying to be devil's advocate. I really like the trijet concept.



"There are no stupid questions, but there are a lot of inquisitive idiots."
User currently offlineBrenintw From Taiwan, joined Jul 2006, 1607 posts, RR: 1
Reply 11, posted (7 years 2 months 3 weeks 2 days 19 hours ago) and read 3529 times:

Quoting MDorBust (Reply 9):
Unless you embeded the engine in the rear empenage of the fuselage aft of the pressure bulkhead

Wouldn't that make it unbearably noisy for PAX? I think the 727 was acceptable because it was for shortish hops -- imagine sitting at the back of this hypothetical tri-jet for 18/20 hours SIN-EWR. If the noise was anything like I imagine it would be, I would be a total basket-case by the time I got off the plane (probably at some diversion airport because I'd gone starkers).

I think the noise suppression that would be required would be a major hurdle to this idea.

Quoting MDorBust (Reply 9):
you could put Harrier style ducts on to split the size of the intake between the two sides of the aircraft

What size would those have to be? I doubt it would be very aerodynamically efficient ...



I'm tired of the A vs. B sniping. Neither make planes that shed wings randomly!
User currently offlineFLY2HMO From , joined Dec 1969, posts, RR:
Reply 12, posted (7 years 2 months 3 weeks 2 days 17 hours ago) and read 3498 times:

Quoting Brenintw (Reply 11):
I think the 727 was acceptable because it was for shortish hops -- imagine sitting at the back of this hypothetical tri-jet for 18/20 hours SIN-EWR.

I really didn't find 727s that loud, at least from the inside, and I've had to sit waaay in the back a few times in them. Ya, not as quiet as a 73NG or A320, but far from unbearable I'd say. And from what I've heard, DC-10/MD-11s and Tristars weren't all that bad either.


User currently offlineBrenintw From Taiwan, joined Jul 2006, 1607 posts, RR: 1
Reply 13, posted (7 years 2 months 3 weeks 2 days 17 hours ago) and read 3490 times:

Quoting FLY2HMO (Reply 12):
DC-10/MD-11s and Tristars weren't all that bad either.

I've been in both DC-10s and MD-11s -- and yes, they weren't bad. However, all the noise generating machinery is outside of the fuselage, which makes a big difference I would imagine.

I've been in a 727, but honestly don't remember if it was noisy or not (I was 11, and on my first overseas trip -- I had other things to think about, like how much I was going to enjoy Disney World!)



I'm tired of the A vs. B sniping. Neither make planes that shed wings randomly!
User currently offlineTSS From United States of America, joined Dec 2006, 3065 posts, RR: 5
Reply 14, posted (7 years 2 months 3 weeks 2 days 16 hours ago) and read 3479 times:

Quoting MDorBust (Reply 9):
Unless you embeded the engine in the rear empenage of the fuselage aft of the pressure bulkhead. As long as the fan diameter is smaller than the diameter of the fuselage you could make it fit.

Instead of a single S-duct like the 727 and L-1011 you could put Harrier style ducts on to split the size of the intake between the two sides of the aircraft.

MDorBust, I like the way you think!
I've been toying with a similar idea for an MD-80 sized aircraft with twin engines mounted inside the empenage.

Quoting MDorBust (Reply 9):
Of course, you would have to move the wing further to the rear to compensate for the shift in COG.

It could work. Ditch the T-tail and go with forward canards for elevation control, plus go with smaller rudders on the outboard ends of the wings...not unlike a larger, jet-engined version of a Beech Starship?

Quoting Brenintw (Reply 11):
Wouldn't that make it unbearably noisy for PAX?

I think the noise suppression that would be required would be a major hurdle to this idea.

Not necessarily. A few lavs and a galley between the last row of seats and the rear bulkhead would absorb/block a lot of sound.



Able to kill active threads stone dead with a single post!
User currently offlineGAIsweetGAI From Norway, joined Jul 2006, 933 posts, RR: 7
Reply 15, posted (7 years 2 months 3 weeks 1 day 20 hours ago) and read 3376 times:

Quoting TSS (Reply 14):
It could work. Ditch the T-tail and go with forward canards for elevation control, plus go with smaller rudders on the outboard ends of the wings...not unlike a larger, jet-engined version of a Beech Starship?

Wouldn't this create possible problems relative to the jetways? (unless the canard is behind the door used for boarding- is that a better idea?)



"There is an art, or rather a knack to flying. The knack lies in learning how to throw yourself at the ground and miss."
User currently offlineDEVILFISH From Philippines, joined Jan 2006, 4775 posts, RR: 1
Reply 16, posted (7 years 2 months 3 weeks 1 day 19 hours ago) and read 3361 times:

Quoting Speedracer1407 (Reply 2):
next generation engines (GEnx) are pretty much ready to go in the next year or so, but aren't available in the thrust class necessary for a twin of 777-748 size. Seems to me like developting a 100Klb + NG engine will be very expensive, considering the already high price and and advanced techonolgies used in the GE90, so perhaps development costs saved by installing three existing, highly efficient engines

Simplifying like mad, three 90Klb thrust GEnx2 engines should be enough to power a radically lighter 748-sized CFRP airframe. The challenge is finding enough refinements to meet the required 15-20% efficiency increase. This could even increase range and payload. I'm not sure that it would satisfy the OEI criteria.

Quoting Brenintw (Reply 3):
I can't imagine there would be any feasible way of plugging one of those into the tail of an aircraft. A lot of the thrust of the current generation engines comes from those fans chewing up enormous amounts of air ..... a smaller fan diameter would result in lower thrust.

McDD already validated the concept two decades ago. A new, bigger #2 engine could straddle the similarly enlarged tail section of the now 22' wide x 250' long fuselage, hopefully with little detrimental effect from the SUD on intake air, given the increased distance to the fan.

Quoting Brenintw (Reply 3):
Furthermore, the sheer weight of modern high-bypass engines would make CG-management a real bear.

Don't forget the remaining two engines could be hung on the wings of the proportionately larger airframe.

Quoting SEPilot (Reply 7):
But that does not change fan diameter, which would still remain too large to use on the tail.

Considering the 115Klb thrust of the 773ER engine, a smaller diameter fan must be feasible for one rated at 90 Klb. A 10' o.d. engine wouldn't be too big on the tail of a 748 sized plane.

Quoting TrijetsRMissed (Reply 8):
All hopes of a future tri-jet widebody died with McDonnell Douglas. Boeing on the other hand, has not designed a tri-jet in over 45 years. The 727 narrow-body design will not be brought back and it is highly unlikely Boeing will attempt to engineer their first tri-jet widebody at this point.

The knowledge gained from those did not die with them. If anything, the vast advances in technology now give designers the leeway to choose the most efficient ways to tackle typical problems. And speaking of chances, this is just a hypothetical exercise.

Quoting Starlionblue (Reply 10):

And that's one of the things that killed McD. The banjo fitting for the MD-11 was very costly to engineer. Scaling the banjo further for the MD-XX (trijet variant) would have been prohibitibe.

It's not like all the lessons learned there were lost. An interesting challenge would be providing enough directional control without resorting to very large or twin tails, due to the big engine reducing available rudder area. And as already mentioned, the beefing up of the tail section wuld be similarly challenging. IMO, Boeing wouldn't shirk from the cost if they could see a big demand for such an aircraft.

Quoting MDorBust (Reply 9):
Of course the big question remains... WHY? Hasn't the low sales of the A380 and 747-8 taught us about the direction in aircraft size?

The answer may lie within this.....

Quoting Lemurs (Reply 6):
They're not going to want to go for a tri/quad if they can help it at all, in any fashion...and that means they need to make some more big breakthroughs in design and materials to get up to 748 sizes in a twin...

Pending which, they'd have to placate the market's clamour for greater capacities with piecemeal iterations of their current product line, until it's no longer practicable.

Quoting TSS (Reply 14):
not unlike a larger, jet-engined version of a Beech Starship?

Essentially, the one in the last link at the thread's start. Having three of which on top, tells me Boeing couldn't be bothered about MX issues on the No. 2 engine on a conventional trijet. (Although their clients likely would.) All of these of course, from my uneducated layman's view.



"Everyone is entitled to my opinion." - Garfield
User currently offlineTSS From United States of America, joined Dec 2006, 3065 posts, RR: 5
Reply 17, posted (7 years 2 months 3 weeks 1 day 16 hours ago) and read 3342 times:

Quoting GAIsweetGAI (Reply 15):
Wouldn't this create possible problems relative to the jetways? (unless the canard is behind the door used for boarding- is that a better idea?)

It would indeed. Moving the canards rearward solves that problem but lessens their effectiveness, thus creating another problem.



Able to kill active threads stone dead with a single post!
User currently offlineStarlionblue From Greenland, joined Feb 2004, 16991 posts, RR: 67
Reply 18, posted (7 years 2 months 3 weeks 21 hours ago) and read 3258 times:

Quoting TSS (Reply 14):
I've been toying with a similar idea for an MD-80 sized aircraft with twin engines mounted inside the empenage.

Whoa there. Now you're putting both engines next to each other AND in the empennage? The Sioux City victims are here. They'd like a word.  Wink



"There are no stupid questions, but there are a lot of inquisitive idiots."
User currently offlineSEPilot From United States of America, joined Dec 2006, 6817 posts, RR: 46
Reply 19, posted (7 years 2 months 3 weeks 21 hours ago) and read 3254 times:

Quoting DEVILFISH (Reply 16):

Pending which, they'd have to placate the market's clamour for greater capacities with piecemeal iterations of their current product line, until it's no longer practicable.

What clamor for greater capacities? With precisely one model of large to very large aircraft selling better than week-old flapjacks (i.e. the 777-300) I don't see any great demand for bigger airplanes at this time. What there is a great clamor for is greater efficiency, and that is in every aspect. I suspect that the airlines will be happy to wait for new VLA's until there are engines big enough to make them as twins. I also believe that Boeing, at least, will not launch a new program unless they can improve the economics at least 15% over what it is replacing.



The problem with making things foolproof is that fools are so doggone ingenious...Dan Keebler
User currently offlineDEVILFISH From Philippines, joined Jan 2006, 4775 posts, RR: 1
Reply 20, posted (7 years 2 months 3 weeks 19 hours ago) and read 3240 times:

Quoting SEPilot (Reply 19):

What clamor for greater capacities?

I think you answered your own question.....

Quoting SEPilot (Reply 19):
I suspect that the airlines will be happy to wait for new VLA's until there are engines big enough to make them as twins.

So there is that demand - however, they can't help but wait until their requirements could be more efficiently met. I didn't find it necessary to qualify further what you quoted as I had already made the point twice earlier.....

Quoting DEVILFISH (Thread starter):
and the high efficiencies and capacities demanded by the airlines



Quoting DEVILFISH (Reply 16):
The challenge is finding enough refinements to meet the required 15-20% efficiency increase.



"Everyone is entitled to my opinion." - Garfield
User currently offlineTSS From United States of America, joined Dec 2006, 3065 posts, RR: 5
Reply 21, posted (7 years 2 months 3 weeks 19 hours ago) and read 3236 times:

Quoting Starlionblue (Reply 18):
Whoa there. Now you're putting both engines next to each other AND in the empennage?

With rudders on the outboard ends of the wings and forward canards for pitch control, why not? There would be few if any hydraulic lines that far rearward in the fuselage.



Able to kill active threads stone dead with a single post!
User currently offlineSEPilot From United States of America, joined Dec 2006, 6817 posts, RR: 46
Reply 22, posted (7 years 2 months 3 weeks 11 hours ago) and read 3192 times:

Quoting TSS (Reply 21):
With rudders on the outboard ends of the wings and forward canards for pitch control, why not? There would be few if any hydraulic lines that far rearward in the fuselage.

The fact that all commercial airliners since the earliest days have had essentially the same layout is not an accident. Different layouts (canards, flying wings, etc.) have advantages but they also have very real disadvantages. The canard layout has been widely touted as being "stall-proof" and when correctly loaded it is; but the downside is a very restricted CG range compared to a conventional layout. I do not believe that the airlines would accept this; they have enough problems with CG as it is. Putting rudders at the ends of the wings has structural (i.e. weight) penalties. The flying wing (read BWB) concept is actually the one that holds the most promise for the future; the primary problem is passenger acceptance of having no windows. When first introduced it was not practical because stalls were pretty much unrecoverable, but with FBW technology that is not such a factor. If Y3 turns out to be a BWB there is the possibility that it could be a trijet; but I don't think it is likely as Boeing does not believe that the public is ready for it. But if an airliner bigger than the A380 ever is built my bet is that it will be a BWB. Of course one big disadvantage to the BWB is that it is one size; different size variations are impossible.



The problem with making things foolproof is that fools are so doggone ingenious...Dan Keebler
User currently offlineStarlionblue From Greenland, joined Feb 2004, 16991 posts, RR: 67
Reply 23, posted (7 years 2 months 2 weeks 6 days 22 hours ago) and read 3124 times:

Quoting SEPilot (Reply 22):
Of course one big disadvantage to the BWB is that it is one size; different size variations are impossible.

I guess that depends on the level of blend. A pure flying wing is tricky to resize. But if you make it a semi-blend with a partly distinct fuse, changing the fuse length becomes possible.



"There are no stupid questions, but there are a lot of inquisitive idiots."
User currently offlineOkelleynyc From United States of America, joined Feb 2006, 219 posts, RR: 0
Reply 24, posted (7 years 2 months 2 weeks 6 days 19 hours ago) and read 3089 times:

This may sound really dumb, but I have an excuse, I'm no aeronautical engineer...

Would it be possible to have a large centerline engine used primarily for cruise and two smaller wing mounted augmenter engines for take off, landing and redundancy in case of the "main" engines failure? The smaller bypass engines could be in clam shelled housings to reduce drag when not need during cruise?

I realize it's a bit goofy and may be too complex, but who's to say that all three engines have to be the same thrust rating and capable of operating throughout the full continuum of flight?

Just another hair-brained thought....



Just give me my Vario, my Ozone Mojo and a gorgeous day of soaring.
25 Post contains links and images Starlionblue : Neat idea. You've solved the windmilling problem of an idle turbofan by putting it in a clam. However you haven't removed the complex and heavy cente
26 CoolGuy : I always assumed that trijets are inefficient (only the center one though) given the possibility of dual engines.
27 Starlionblue : Weeeeeellll... When the aircraft is too large for a twin, a triplet is a good option unless you count engine placement. If the third engine could be
28 Post contains images Brenintw : OK, either I'm blind, or stupid (or both) -- but I'm not sure where the 4th engine is on that -- and why was it "infamous"? Enquiring minds want to k
29 TrijetsRMissed : All three engines are the same, just the No.2 is shaped differently for obvious reasons. For example, an MD-11 may have three PW4462's, 62,000lb of t
30 Post contains links and images Rwessel : The three main engines on the Trident (RR Spey 512s – 10,050-11,960lbs thrust, depending on the model) were mounted similarly to those on a 727. On
31 SEPilot : But what would be the point? Weight would be pretty close to the same, structure would be the same, and trip costs would be pretty much the same. You
32 Post contains links and images Starlionblue : It's "infamous" in the same way h VFW-614 engine placement is "dreaded". Just in my own mind in other words. Both are fugly and inelegant solutions i
33 Post contains links and images MrFord : And the 4 side-by-side main gear wheels... British design at it's best lol! Well, still better than this... View Large View MediumPhoto © Andy M
34 Post contains links Starlionblue : Oddly, I've always found the Victor breathtaking despite being really weird. The next to last pic on this page http://www.thunder-and-lightnings.co.u
35 Post contains images Areopagus : It would fit right in with a squadron of (some marks of) Canberras.
36 Post contains images SEPilot : Wow, that one looks straight out of a Hollywood special effects department on LSD!
37 Starlionblue : Viciously cool looking up close and personal. And it has the same gorgeous fin/stab as the VC-10.
38 Post contains images MrFord : You have to give them, they really tried to 'think outside the box' hehe! Nice site there, thanks! I've read somewhere before about the Falkland Isla
39 Post contains links and images Starlionblue : Mostly I find all the references to how the government slowly killed the UK aviation industry fascinating and disturbing. Those guys seemed to change
40 Post contains images MrFord : But then I don't know much of the history of the Conway or the Sapphire, for that matter... Just that I saw that, I may be wrong hehe! But you're rig
41 Starlionblue : And despite that all that, the UK still had kick-ass aircraft that allowed it to project force in the South Atlantic in the 1980s. Can't keep good de
42 Post contains images MrFord : That should give you access to Elite status on you frequent flyer account with that ! Congrats, you're now officially addict !
43 Cloudy : I've never heard this seriously proposed - however Boeing did propose a "thrusting APU" for the 777. This engine would fulfill all the normal functio
44 Post contains images Starlionblue : Well, there was the aforementioned Trident. Incidentally, there have been several military jets with dual propulsion, both in service and proposed. -
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