zipped Posted March 21, 2011 Share Posted March 21, 2011 First landing of B747-8i at KBFIThis guy has a great gig going in the Seattle area.http://blog.seattlepi.com/airlinereporter/ Link to comment Share on other sites More sharing options...
Southshore Posted March 21, 2011 Share Posted March 21, 2011 Whoa - honkin' machine. At least they can get that one off the ground.Question for the smart folks - what is the dealeo with winglets? Do they work or what? The 'Bus's have the little triangles, the '47-400, '37's etc have the the big honkin' blended jobbies, the '77 has nada and now the 47-800 has the sweptback dealies with no upturn at all. So what is the science behind all this? If they work, you'd think there would be some 'best fit' answer. How do they calculate the benefit?It makes me think there is a bit of an 'arm wave' going on about where the benefit lies. I mean, to make ice - take water and freeze it. Boom, you got ice. Simple. Anybody?Thanks Link to comment Share on other sites More sharing options...
Seeker Posted March 21, 2011 Share Posted March 21, 2011 I just wish Boeing had built this 10 years ago, then we wouldn't have to look at the butt-ugly 380 in YYZ twice a week. Link to comment Share on other sites More sharing options...
cavok Posted March 21, 2011 Share Posted March 21, 2011 ...the '77 has nada and now the 47-800 has the sweptback dealies with no upturn at all.The 777 has a sweptback winglets as well. ACA 77WJudging by the video posted here, they appear to be very similar to those on the 747-8. Link to comment Share on other sites More sharing options...
Southshore Posted March 21, 2011 Share Posted March 21, 2011 The 777 has a sweptback winglets as well. ACA 77WI stand corrected. Never noticed that before. Link to comment Share on other sites More sharing options...
boestar Posted March 21, 2011 Share Posted March 21, 2011 It has alot to do with the design of the wing itself. Winglets are used where a wing develops significant vorticies at the tip which reduces the efficiency of the oouter portion of the wing. The winglet eliminates this issue causing an increase in efficiency.Newer more efficient wing designs already reduce the inefficiencies therefore negating the need for the winglet. The original 747-400 had the same wing as the -200 only with a few added ribs at the outboard end. That wing was developed in the 60s the winglet compensated for the inefficiencies of the design. Link to comment Share on other sites More sharing options...
Southshore Posted March 21, 2011 Share Posted March 21, 2011 It has alot to do with the design of the wing itself. Winglets are used where a wing develops significant vorticies at the tip which reduces the efficiency of the oouter portion of the wing. The winglet eliminates this issue causing an increase in efficiency.Yeah, I knew why they're used but wonder about the different applications of the technology. If the Bus design is effective, wouldn't Boing want to develop somethng similar? The weight penalty, collision risk (it's happened more than once) etc, be motivation to go to a design smaller than those tip sails? I can imagine the new cadcam wings have lots of those problems solved. PFMThanks Link to comment Share on other sites More sharing options...
ILB Posted March 22, 2011 Share Posted March 22, 2011 I believe they are called "raked wingtips" and according to WIKIPEDIA, they reduce drag by 5.5%, compared to 3.5 to 4.5% for more traditional blended winglets. Link to comment Share on other sites More sharing options...
cavok Posted March 22, 2011 Share Posted March 22, 2011 I believe they are called "raked wingtips" and according to WIKIPEDIA, they reduce drag by 5.5%, compared to 3.5 to 4.5% for more traditional blended winglets.Another consideration with the A320 and B737 families is that raked winlets (as opposed to blended winglets) would place them into Code D aircraft territory, thus necessitating greater wingtip clearances on apron surfaces.As I recall, there were some early designs of the 777 with folding wing tips which would have allowed the aircraft to park on a Code D stand. Such a design feature would almost certainly be heavily considered if the 737 replacement utilizes a larger wingspan. Of course, it might be easier to adjust ICAO's clearance distances... Link to comment Share on other sites More sharing options...
AAS Posted March 22, 2011 Share Posted March 22, 2011 I just wish Boeing had built this 10 years ago, then we wouldn't have to look at the butt-ugly 380 in YYZ twice a week. Three times a week Link to comment Share on other sites More sharing options...
JL Posted March 23, 2011 Share Posted March 23, 2011 For raked wingtips/winglets don't forget the 767-400 as well. Another reason for this design is possibly related to trying to achieve a more elipitical planform for the wing. The eliptical wing achieves the least amount of induced drag (without winglets) by producing an elliptical lift distribution which allows the bound vortex to transition to the trailing vortex in a smoother fashion. Link to comment Share on other sites More sharing options...
Maverick Posted March 23, 2011 Share Posted March 23, 2011 Three times a weekWe should been allowed to see it daily! Link to comment Share on other sites More sharing options...
Southshore Posted March 23, 2011 Share Posted March 23, 2011 For raked wingtips/winglets don't forget the 767-400 as well. Another reason for this design is possibly related to trying to achieve a more elipitical planform for the wing. The eliptical wing achieves the least amount of induced drag (without winglets) by producing an elliptical lift distribution which allows the bound vortex to transition to the trailing vortex in a smoother fashion.Well, that just made my head hurt. Ooo, look, a puppy! Link to comment Share on other sites More sharing options...
JL Posted March 24, 2011 Share Posted March 24, 2011 I agree Southshore. Typically, I subscribe to the "if it looks pretty, it'll fly great" theory of flight. Link to comment Share on other sites More sharing options...
Seeker Posted March 24, 2011 Share Posted March 24, 2011 I agree Southshore. Typically, I subscribe to the "if it looks pretty, it'll fly great" theory of flight.Similar to the TLAR construction philosophy that I've used with much success my whole life. TLAR: That Looks About Right. Link to comment Share on other sites More sharing options...
JL Posted March 25, 2011 Share Posted March 25, 2011 Seeker, hopefully your TLAR technique was better than my Dad's which was to overbuild by about 800%! Why use the recommended 1/8th plywood when they make 3/4 inch! Link to comment Share on other sites More sharing options...
Seeker Posted March 25, 2011 Share Posted March 25, 2011 Seeker, hopefully your TLAR technique was better than my Dad's which was to overbuild by about 800%! Why use the recommended 1/8th plywood when they make 3/4 inch!I think you'll find, if you do the math, that substituting 3/4 for 1/4 is only overbuilding by 600% so it's not really quite as bad as you make it sound. Link to comment Share on other sites More sharing options...
JL Posted March 25, 2011 Share Posted March 25, 2011 Seeker, are you my dad? Link to comment Share on other sites More sharing options...
Seeker Posted March 25, 2011 Share Posted March 25, 2011 JL, the cost and effort required to build something and then re-build it because it wasn't strong enough is greater than the cost and effort required to build it "RIGHT" the first time. (maybe I am your Dad!). Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.