Sponsor Message:
Aviation Technical / Operations Forum
My Starred Topics | Profile | New Topic | Forum Index | Help | Search 
Could The 747ADV Be A Twin?  
User currently offlineTockeyhockey From United States of America, joined Feb 2005, 950 posts, RR: 0
Posted (9 years 3 months 3 weeks 1 day 18 hours ago) and read 3826 times:

Let's say that the 747ADV uses a new, all-composite fuselage that allows it to drop an amount of weight proportional to change in weight when you compare the 767 to the 787.

Now, what if you strapped a couple of GE90s to the new, super light jumbo. Would the thrust be sufficient to turn the 747ADV into the worlds only jumbo-twin?

20 replies: All unread, jump to last
 
User currently offlineGlom From United Kingdom, joined Apr 2005, 2815 posts, RR: 10
Reply 1, posted (9 years 3 months 3 weeks 1 day 17 hours ago) and read 3806 times:

The 747ADV wouldn't be a twin because it would change the 747 design too much, particularly all the stuff you propose. But any cleansheet 747 replacement will almost certainly be a twin. Slightly more powerful GE90s might indeed do the job if the aircraft in question was plastic.

User currently offlineAerlingus330 From United Kingdom, joined Nov 2004, 834 posts, RR: 1
Reply 2, posted (9 years 3 months 3 weeks 1 day 17 hours ago) and read 3792 times:

The GE90s has a Thrust Range of 75 000-127 000 pounds.
The Current member of the 747 Family has engines with 60 000 pounds of thrust. So, 60 000 X 4= 240 000 pounds of thrust.
Lets Take the Normal Thrust of the GE90s, which is around 110 000 pounds.
110 000 X 2 = 220 000.

Conclusion
If Boeing could get the Weight of the Boeing 747adv to below the weight of the current 747-400 then It may work. However, This would make the 747ADV severely underpowered and have no Back up in an emergency. The 747 Has no chance ever having 2 Engines. It would work, but it would be dangerous.

AerLingus330



Aer Lingus Airbus A330-300
User currently offline411A From United States of America, joined Nov 2001, 1826 posts, RR: 8
Reply 3, posted (9 years 3 months 3 weeks 1 day 9 hours ago) and read 3710 times:

IF the B747 was to be re-designed as a 'twin', the entire wing would need to be re-designed, due mainly to wing bending relief considerations...IE; additional weight outboard on the wing would not be sufficient, with only two engines.
Additional wing structure would be required...IE, much heavier.


User currently offlineStarlionblue From Greenland, joined Feb 2004, 17030 posts, RR: 67
Reply 4, posted (9 years 3 months 3 weeks 1 day 6 hours ago) and read 3680 times:

Quoting Aerlingus330 (Reply 2):
The GE90s has a Thrust Range of 75 000-127 000 pounds.
The Current member of the 747 Family has engines with 60 000 pounds of thrust. So, 60 000 X 4= 240 000 pounds of thrust.
Lets Take the Normal Thrust of the GE90s, which is around 110 000 pounds.
110 000 X 2 = 220 000.

Conclusion
If Boeing could get the Weight of the Boeing 747adv to below the weight of the current 747-400 then It may work. However, This would make the 747ADV severely underpowered and have no Back up in an emergency. The 747 Has no chance ever having 2 Engines. It would work, but it would be dangerous.


Sorry but your math is a bit off. If a quad has 4 x 60 000 lb of thrust, an equivalent twin would need 2 x 180 000 of thrust in order to ensure the same engine out performance. So you're way beyond "it would work". Apart from the fact that such engines are quite a bit beyond maximal current capabilities (a 50% increase in thrust, no less) I can hear the wings being ripped off right now  Wink


Also, while the GE90 may have benched over 120 000 lb, the highest thrust version in production delivers 115 000 lb. It's one thing to perform for a few hours in the test rig. It's another to deliver the same performance for years hanging under a wing.

[Edited 2005-05-14 07:57:20]

[Edited 2005-05-14 07:58:22]


"There are no stupid questions, but there are a lot of inquisitive idiots."
User currently offlineTockeyhockey From United States of America, joined Feb 2005, 950 posts, RR: 0
Reply 5, posted (9 years 3 months 2 weeks 2 days 18 hours ago) and read 3473 times:

Quoting Aerlingus330 (Reply 2):
It would work, but it would be dangerous.

twins have, on average, a higher safety record than quads. boeing pushed really hard to make the 777 a twin, even though everyone at the time thought it was crazy. the 777 has been an astounding success. who is to say that boeing wouldn't push hard on the 747A?

twins are more efficient, require less maintenance, and are safer.


User currently offlineSanjet From Canada, joined Mar 2005, 180 posts, RR: 0
Reply 6, posted (9 years 3 months 2 weeks 2 days 17 hours ago) and read 3461 times:

Quoting Tockeyhockey (Reply 5):
twins are more efficient, require less maintenance, and are safer.

Don't want to sound to gritty but twins have a more stringent maintenance standard than quads to keep ETOPS certification. Although yes it might require less manhours total since you only have 2 engines, the work on a per engine basis would be higher on a twin.  bigthumbsup 



Will Fly For Food!
User currently offlineBhill From United States of America, joined Sep 2001, 966 posts, RR: 0
Reply 7, posted (9 years 3 months 2 weeks 2 days 11 hours ago) and read 3395 times:

Yup....411, I was gonna pose that posit...not just the "static" load on the wings but the moments of force at the mounting points...


Carpe Pices
User currently offlineCWUPilot From United States of America, joined Feb 2004, 126 posts, RR: 0
Reply 8, posted (9 years 3 months 2 weeks 1 day 22 hours ago) and read 3298 times:

True, it wouldn't work or get certified with 2 110,000 lb engines since single engine climb performance would be too low. But this is a good idea and Boeing will almost surely use a twin for its next "Jumbo Jet".

-CWUPilot



"The worst day of flying still beats the best day of real work."
User currently offlineBoeing Nut From , joined Dec 1969, posts, RR:
Reply 9, posted (9 years 3 months 2 weeks 1 day 17 hours ago) and read 3259 times:

Um, I hate to break it to you guys, but this concept is already flying!


Modified Airliner Photos:
Click here for bigger photo!
Design © Robert Fall
Template © Daniel & Robert Fall



 duck 

 Big grin


User currently offlineStarlionblue From Greenland, joined Feb 2004, 17030 posts, RR: 67
Reply 10, posted (9 years 3 months 2 weeks 1 day 14 hours ago) and read 3227 times:

Quoting Tockeyhockey (Reply 5):
twins have, on average, a higher safety record than quads.

I find that hard to believe. I think stats will show they are about as safe.

Quoting CWUPilot (Reply 8):
But this is a good idea and Boeing will almost surely use a twin for its next "Jumbo Jet".

Never say never but we're getting into diminishing returns on the R&D costs. Why develop a 180 000lb engine for a single aircraft? Sure, the GE90-115B is only for one aircraft, but it's not that far beyond other versions of the same engine. To ask for an extra 50% (which more or less demands a clean sheet design) when the number of airframes sold will be pretty low seems economically unwise.



"There are no stupid questions, but there are a lot of inquisitive idiots."
User currently offlineTockeyhockey From United States of America, joined Feb 2005, 950 posts, RR: 0
Reply 11, posted (9 years 3 months 1 week 5 days 18 hours ago) and read 3097 times:

Quoting Boeing Nut (Reply 9):
Um, I hate to break it to you guys, but this concept is already flying!

boeing nut, do you have any additional background on this? is this a real test for the future of the 747, or were they just testing the 777 wings?

any and all information would be greatly appreciated!!!


User currently offlineBoeing Nut From , joined Dec 1969, posts, RR:
Reply 12, posted (9 years 3 months 1 week 5 days 18 hours ago) and read 3088 times:

Quoting Tockeyhockey (Reply 11):
boeing nut, do you have any additional background on this? is this a real test for the future of the 747, or were they just testing the 777 wings?

 bitelip 

Dude, that's a what I thought would be an obvious joke.


User currently offlineTockeyhockey From United States of America, joined Feb 2005, 950 posts, RR: 0
Reply 13, posted (9 years 3 months 1 week 5 days 17 hours ago) and read 3076 times:

so you're saying the photo was a fake? or is it a test of the 777 wing?

thanks for getting my hopes up. i'm excited about the prospects of seeing engines larger and more powerful than the ge90.


User currently offlineBoeing Nut From , joined Dec 1969, posts, RR:
Reply 14, posted (9 years 3 months 1 week 5 days 16 hours ago) and read 3066 times:

Yes, it's a fake. Click on it and you'll find a lot more. Some are rather hysterical.

User currently offlineUAL747 From , joined Dec 1969, posts, RR:
Reply 15, posted (9 years 3 months 1 week 4 days 17 hours ago) and read 2954 times:

Obviously the pic is a fake, but whoever did it, did a great job. Almost looks believable, if you didn't know much about aviation!

UAL


User currently offlineSeptember11 From United States of America, joined May 2004, 3623 posts, RR: 21
Reply 16, posted (9 years 3 months 1 week 4 days 17 hours ago) and read 2946 times:

Quoting UAL747 (Reply 15):
Obviously the pic is a fake, but whoever did it, did a great job. Almost looks believable, if you didn't know much about aviation!

you got that right!!



Airliners.net of the Future
User currently offlineGQfluffy From , joined Dec 1969, posts, RR:
Reply 17, posted (9 years 3 months 1 week 4 days 13 hours ago) and read 2912 times:

Quoting Tockeyhockey (Reply 5):
twins have, on average, a higher safety record than quads.

LOL  rotfl  Um, you do realize that quads have been around for 50 years, while twins about half that. It's like comparing apples and oranges...


Like others have said... If you turn the 747adv into a twin, you're talking about $$$ being sunk into a new wing and other fuselage changes, not to mention waiting at least a year for engines to be built, and tested. That alone would kill the twin 747adv. At that point...why even bother calling it a 747? Just start with a new design. Easier and cheaper in the long run. If I'm reading what I've seen about the 747adv correctly, its a simple stretch, with new technology, wing improvements, and new engines.

LoL, you've also made my day with that 747 rewinged with 777 wings. HAHAHA! Don't take offense! It was just funnier then...well....alot of things...

fluffy


User currently offlineTockeyhockey From United States of America, joined Feb 2005, 950 posts, RR: 0
Reply 18, posted (9 years 3 months 1 week 3 days 18 hours ago) and read 2832 times:

i guess i'm the sucker of the day here at good old airliners.net.

at least give me this -- that is one hell of a good fake photo.


User currently offlineZvezda From Lithuania, joined Aug 2004, 10511 posts, RR: 64
Reply 19, posted (9 years 3 months 5 days 19 hours ago) and read 2678 times:

Let's approach the original question a little bit differently. Given B787 composite technologies, could a B747-400 sized plane be designed to use two GE90s?

The GE90 has been tested at 127,000 lbs. of thrust and certified to 115,100 lbs. For the sake of argument, let's assume at it can be certified to 120,000 lbs. at a reasonable cost.

The B777-300ER has an OEW of 370,000 lbs and a MTOW of 775,000 lbs. The B747-400 has an OEW of about 395,000 lbs and a MTOW of 875,000 lbs.

Could a new design twin with 120,000 lb engines perform all the missions of a B747-400? The assumed increase in thrust would mean that our twin could have a MTOW of 810,000 lbs. The switch to composite construction would probably yield an OEW of about 350,000 lbs. With a max structural payload of 154,000 lbs (same as B777-300ER and slightly higher than the B747-400), 400,000 lbs of fuel could be carried (more than either the B777-300ER or B747-400).

So, yes, an all-new twin the size of the B747-400 could almost certainly be built using GE-90s. Of course, it wouldn't be a B747.

[Edited 2005-05-30 19:24:46]

User currently offlineZRH From Switzerland, joined Nov 1999, 5566 posts, RR: 36
Reply 20, posted (9 years 3 months 5 days 19 hours ago) and read 2719 times:

No. It would be an almost entirely new aircraft. They would not name it 747Adv but probably 797 an would cost a lot.

Top Of Page
Forum Index

Reply To This Topic Could The 747ADV Be A Twin?
Username:
No username? Sign up now!
Password: 


Forgot Password? Be reminded.
Remember me on this computer (uses cookies)
  • Tech/Ops related posts only!
  • Not Tech/Ops related? Use the other forums
  • No adverts of any kind. This includes web pages.
  • No hostile language or criticizing of others.
  • Do not post copyright protected material.
  • Use relevant and describing topics.
  • Check if your post already been discussed.
  • Check your spelling!
  • DETAILED RULES
Add Images Add SmiliesPosting Help

Please check your spelling (press "Check Spelling" above)


Similar topics:More similar topics...
Could This Sound Be The Apu? posted Sun May 13 2001 22:53:06 by TurboTristar
Could The Concorde Do A Loop? posted Fri Oct 20 2006 23:22:53 by Vio
Could The 757 Operate Safely From Eyw? posted Thu Dec 19 2002 21:15:21 by John
When Should The Doors Be Armed Or Disarmed? posted Thu Aug 22 2002 21:19:41 by Hamad
Could The Space Shuttle Do Normal Flights? posted Thu Apr 25 2002 18:15:04 by Sushka
When Will The A3XX Be Finished? posted Fri Nov 3 2000 15:18:13 by MD11man
What Was Going To Power The Twin Engine 727? posted Fri May 26 2006 18:29:04 by 747400sp
In The Cruise Engine Failure Twin Question posted Mon May 22 2006 00:24:08 by JulianUK
Can A Jet Be Damaged When Exiting The Jetstream? posted Wed Apr 12 2006 23:35:30 by Rolfen
The Effects Of The 12 Vmc On A "normal" Light Twin posted Mon Feb 27 2006 15:08:07 by NorCal

Sponsor Message:
Printer friendly format