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747-400 Domestic... No Winglets?

Mon Jan 22, 2001 12:16 pm

http://www.boeing.com/commercial/747-400d/product.html

Why doesn't the Boeing 747-400d have winglets? I have heard that the winglets don't really help enough to make a difference, is this true?
 
Guest

RE: 747-400 Domestic... No Winglets?

Mon Jan 22, 2001 12:31 pm

What winglets do is break up wingtip vortices, which cause drag. This trick helps increase the range by like 5% or something. The 747-400D flies much much shorter flights, so the "range extending" winglets aren't really needed, as their only purpose on the -400D is adding weight.
 
Mit
Posts: 165
Joined: Tue Dec 19, 2000 6:48 am

RE: 747-400 Domestic... No Winglets?

Mon Jan 22, 2001 12:34 pm

Yes. The weight penalty of the winglets is only offset on longer flights. (They're deceptively large -- over six feet tall!) The plan of most 747 domestic operators is to use the planes until they have relatively low hours and high cycles. At that point, they can have the winglets added and put into international service where they will accumulate lots of hours but not many cycles.

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