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arrow28
9th Feb 2010, 11:06
Did a search but need some answers please.

1. Do winglets increase the RTOW
2. Reduce the take-off run
3. What segment of the take-off do winglets give the most benefit.
4. Could an a/c depart with a winglet missing and what would be the penalties

Thanks arrow

alexban
9th Feb 2010, 12:24
maybe this should help:

Aero 17 - Blended Winglets (http://www.boeing.com/commercial/aeromagazine/aero_17/winglet_story.html)

welliewanger
9th Feb 2010, 12:25
1. Theoretically - yes (if the limit is imposed by lift available. Limit is more likely to be due to structural issues). In practice (legally) probably not. Athough I don't know for sure.

2. See above.

3. Dunno.

4. Yes. Check the MEL for your particular aircraft first though. Penalty would be slightly increased fuel burn (I'm told that winglets reduce burn by 7%) And aileron trim issues.

flyjet787
9th Feb 2010, 18:13
3. I think it would be the part where the wing tip vortices would be maximum. I am guessing it's immediatly after lift off and climb. Basically what winglets do is reduce the wingtip vortices and there by reduce induced drag.

Induced Drag= Lift(squared) x Wing Span(squared) / Velocity of Aircraft(squared).

QJB
9th Feb 2010, 23:33
Induced Drag= Lift(squared) x Wing Span(squared) / Velocity of Aircraft(squared).

Don't you mean:

[0.318(CL^2/pi*AspectRatio*efficiencyfactor)]*q*s

J

Empty Cruise
10th Feb 2010, 10:06
1) Depends - if you're 2nd segment limited, they will.
2) Theoretically, yes. Weather Boeing have bovvered with supplying the new data is another kettle of fish.
3) 2nd segment
4) Yes - CDL, notr MEL, applies. Weight restrictions galore etc etc, but easily doable (unless you're close to margins anyway)