Tarantine
Topic Author
Posts: 208
Joined: Tue Sep 19, 2000 12:53 pm

Winglets?

Tue Sep 19, 2000 1:34 pm

Most of the new aircraft from the 1980's like the 747-400, MD-11 & all the Airbus types were equipped with winglets. I thought that they reduced fuel burn. Why then did Boeing (and also Douglas on the MD-90) decide not to put them on their newer aircraft?
 
Guest

RE: Winglets?

Wed Sep 20, 2000 1:34 am

I think there are several factors that affect the decisions whether to add winglets or not.

1. Cost is definitely the number one issue. To build a winglet you first have to design, build and test it then to certify it.

2. Advantages due to addition of winglets have in terms of fuel saving compared to cost and the addition of weight.

As I understand it, winglets can reduce drag only at one or two flying conditions (e.g., during cruise) and not during other phases. Depending on the design and type of operations, the net advantage of winglets may not be that great. I think in the case of the MD-90, McD Douglas simply did not want to deal with designing and building a new winglet for the MD-90 since it's a relatively short range aircraft anyway. In the case of the 777 , with a new wing (not modified from other models), Boeing feels that a winglet is not needed (keep in mind that if you can add, say 5 ft to a wing, it is more efficient to add it outward than upward (winglet)).

Best Regards,
Nut
 
boomer
Posts: 108
Joined: Thu May 27, 1999 2:59 am

RE: Winglets?

Thu Sep 21, 2000 11:53 am

Dead-on MD11Nut. I just wanted to add a note. There are many aerodynamic tricks that can be used to save fuel, not just winglets. Just look at the raked wingtips on the B767-400ER.


Click for large version
Click here for full size photo!

Photo © Thomas Millard



The wing structure required to support the loads a winglet places on the wing is costly and is not easily recovered by the puddle jumper operation of short and mid-range aircraft. Even long-range aircraft like the 767 have obvious design related cost trade-offs that drove Boeing to decide to rake the wingtip instead of putting a winglet on it.

If there was only one right way to do things in this business, all aircraft would have wing mounted engines, fowler flaps, and cabin doors that retract inside the fuselage ceiling.

Who is online

Users browsing this forum: caoimhin, Francoflier, StereoTechque and 3 guests

Popular Searches On Airliners.net

Top Photos of Last:   24 Hours  •  48 Hours  •  7 Days  •  30 Days  •  180 Days  •  365 Days  •  All Time

Military Aircraft Every type from fighters to helicopters from air forces around the globe

Classic Airliners Props and jets from the good old days

Flight Decks Views from inside the cockpit

Aircraft Cabins Passenger cabin shots showing seat arrangements as well as cargo aircraft interior

Cargo Aircraft Pictures of great freighter aircraft

Government Aircraft Aircraft flying government officials

Helicopters Our large helicopter section. Both military and civil versions

Blimps / Airships Everything from the Goodyear blimp to the Zeppelin

Night Photos Beautiful shots taken while the sun is below the horizon

Accidents Accident, incident and crash related photos

Air to Air Photos taken by airborne photographers of airborne aircraft

Special Paint Schemes Aircraft painted in beautiful and original liveries

Airport Overviews Airport overviews from the air or ground

Tails and Winglets Tail and Winglet closeups with beautiful airline logos