Sponsor Message:
Aviation Technical / Operations Forum
My Starred Topics | Profile | New Topic | Forum Index | Help | Search 
Why No Winglets For Class B747?  
User currently offlineWarren747sp From United States of America, joined Feb 2004, 1160 posts, RR: 0
Posted (5 years 11 months 2 days 18 hours ago) and read 7577 times:

I was in JNB recently and looking at all the 743 and 742 parked all over. I would imagine if winglets were installed planes like the 743 it could possibly be made competitive again on certain routes. any comments?


747SP
10 replies: All unread, jump to last
 
User currently offlineFlyf15 From , joined Dec 1969, posts, RR:
Reply 1, posted (5 years 11 months 2 days 18 hours ago) and read 7568 times:

I actually recall seeing a picture a while back of an ex-FedEx 747 with aviation partners winglets fitted. They were huge.

But, my guess is there simply isn't the demand. There aren't really that many 747 classics out there anymore, they're not a main component of the world fleet like 737s, 757s, and 767s.


User currently offlineA342 From Germany, joined Jul 2005, 4681 posts, RR: 3
Reply 2, posted (5 years 11 months 2 days 16 hours ago) and read 7543 times:

Aviation Partners developed a winglet solution for the 747 Classic and flight-tested them. The programme was shelved in 2000 or 2001.

I fear winglets alone aren't enough to make them compeitive again. Their time is slowly running out.



Exceptions confirm the rule.
User currently onlineCrimsonNL From Netherlands, joined Dec 2007, 1861 posts, RR: 42
Reply 3, posted (5 years 11 months 2 days 15 hours ago) and read 7513 times:
AIRLINERS.NET CREW
CHAT OPERATOR

In front of the Seattle Museum of Flight, is a huge blended winglet for the 747Classic on display, I would have loved to see those in action!


Nothing's worse then flying the same registration twice, except flying it 4 times..
User currently offlineFlighty From United States of America, joined Apr 2007, 8491 posts, RR: 2
Reply 4, posted (5 years 11 months 2 days 13 hours ago) and read 7466 times:

The thirsty engines -- and 3 man cockpit -- and large maintenance costs mean that the 747 classic is completely uncompetitive, with or without winglets.

User currently offlineTdscanuck From Canada, joined Jan 2006, 12709 posts, RR: 80
Reply 5, posted (5 years 11 months 2 days 10 hours ago) and read 7434 times:



Quoting Warren747sp (Thread starter):
I was in JNB recently and looking at all the 743 and 742 parked all over. I would imagine if winglets were installed planes like the 743 it could possibly be made competitive again on certain routes. any comments?

In addition to all of the above, the 747 isn't a very good application for blended winglets. It's not span restricted and it's already got a very long wing. For the same reasons that you don't put winglets on a 777 or 787, you wouldn't want to on a 747. Raked wingtips maybe, if the wing has enough residual structural margin.

Tom.


User currently offlineA342 From Germany, joined Jul 2005, 4681 posts, RR: 3
Reply 6, posted (5 years 11 months 1 day 15 hours ago) and read 7318 times:



Quoting Tdscanuck (Reply 5):
In addition to all of the above, the 747 isn't a very good application for blended winglets.

IIRC, they achieved a fuel burn reduction of at least 5% on the 747.

Quoting Tdscanuck (Reply 5):
For the same reasons that you don't put winglets on a 777 or 787

Installing a blended winglet must be worthwhile on 787-3, otherwise they wouldn't do it. And isn't Aviation Partners studying a retrofit programme for the 777"Classic"?



Exceptions confirm the rule.
User currently offlineTdscanuck From Canada, joined Jan 2006, 12709 posts, RR: 80
Reply 7, posted (5 years 11 months 1 day 12 hours ago) and read 7269 times:



Quoting A342 (Reply 6):

Quoting Tdscanuck (Reply 5):
For the same reasons that you don't put winglets on a 777 or 787

Installing a blended winglet must be worthwhile on 787-3, otherwise they wouldn't do it. And isn't Aviation Partners studying a retrofit programme for the 777"Classic"?

787-3 is span restricted, which is why they'd go for winglets over raked tips. For the early 777's they may not have enough margin to support a raked wingtip...that causes more additional load on the wing than a blended winglet.

Tom.


User currently offlineA342 From Germany, joined Jul 2005, 4681 posts, RR: 3
Reply 8, posted (5 years 11 months 1 day 12 hours ago) and read 7266 times:



Quoting Tdscanuck (Reply 7):

I agree. But my point was that having blended winglets on a 747 is better than no wingtip device at all.

BTW, what do you mean by "a very long wing"? The length of the wing measured along the main spar, as opposed to half the wingspan?



Exceptions confirm the rule.
User currently offlineTdscanuck From Canada, joined Jan 2006, 12709 posts, RR: 80
Reply 9, posted (5 years 11 months 1 day 7 hours ago) and read 7216 times:



Quoting A342 (Reply 8):
But my point was that having blended winglets on a 747 is better than no wingtip device at all.

Fair enough. It's not necessarily true that a winglet is always better than none (some wings can't support the shifted load without taking a hit on MTOW) but, in the 747 case, if it really gives 5% improvement then it's clearly aerodynamically advantageous.

Quoting A342 (Reply 8):

BTW, what do you mean by "a very long wing"? The length of the wing measured along the main spar, as opposed to half the wingspan?

The efficacy of a winglet, assuming that's it's designed properly, isn't proportional to the size of the winglet, it's proportional to the ratio of the winglet size to the wing size. So sticking a 737 winglet on a 747 gives you a lot less proportional advantage. The longer your wing is, the larger your winglet needs to be to realize the equivalent benefit. Since the 747 already has a very large wing, it needs a very large (i.e. heavy and expensive) winglet.

Tom.


User currently offlineA342 From Germany, joined Jul 2005, 4681 posts, RR: 3
Reply 10, posted (5 years 11 months 18 hours ago) and read 7134 times:



Quoting Tdscanuck (Reply 9):

Thanks for the answer.

I'll shamelessly steal Aeroweanie's picture, as I can't find it elsewhere.  biggrin 



Here are two articles:


http://www.flightglobal.com/articles...-737-classic-and-747-winglets.html

http://www.flightglobal.com/articles...ssic-winglet-flight-tests-set.html



Exceptions confirm the rule.
Top Of Page
Forum Index

Reply To This Topic Why No Winglets For Class B747?
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...
747-800: Why No Winglets? posted Sat Dec 17 2005 03:29:54 by Thrust
Why No LD2 For Acft Beside 767? posted Sat Sep 3 2005 22:14:07 by A342
Why No Winglets In B777 posted Wed Feb 2 2005 03:03:38 by Aseem
Why No Winglets On The 777? posted Sun Sep 12 2004 12:19:58 by Regis
Why No Winglets On The 737-600 posted Sun Sep 28 2003 00:41:25 by Cancidas
Why No Winglets On The 717? posted Mon Oct 14 2002 21:35:26 by BR715-A1-30
B777 Why No Winglets. posted Wed Nov 14 2001 18:16:01 by HAWK21M
Why No Decompression Training For Civil Pilots? posted Tue May 22 2007 01:35:47 by Ukair
Why No Bigger CRJs For NWA Airlink? posted Wed Nov 30 2005 08:27:01 by AirWillie6475
Why No C-130 Aircraft For Cargo Airlines? posted Fri Mar 18 2005 01:19:54 by PPVRA

Sponsor Message:
Printer friendly format