where is the winglet ?

[152captain]

Surely a missing winglet is a "no go" item?

Air Canada 747-433M (http://www.airliners.net/open.file/414638/M/)


152

[747FOCAL]

Nice fake dude. :mad:

[Panama Jack]

Is it? I thought I recently read that one of Air Canada's B-747 winglets was damaged.

[jed_thrust]

The winglet is not only not required for the -400, there is no performance penalty when it is missing!

Very clever marketing boys at Boeing, wouldn't you say?

Now, the 'Bus has real winglets (ie, ones that have an aerodynamic reason for being there), as I'm sure does the 737 NG.

[gas path]

Sorry, but a missing winglet is allowable under the MEL but there is a performance and fuel penalty for it.
Takes about an hour and a half to remove, a couple of fairings and 3 'pins', cover the holes up with speedtape and away you go!
It can be manhandled on and off but a sling is desirable not overly heavy but it's bigger than it looks:ooh:

[Phil Squares]

Don't want to nit pick, but the winglet is actually there for a purpose. It was added originally as a way to get 12 feet extra wing and keep the a/c footprint the same as the -300. As an aside, the winglets were found to decrease induced drag when compared to the classic wing.

There is a CDL penalty that has to be applied if the winglets are missing.

JAL operates some -400D which are domestic and don't have winglets. Of course, they don't have the same MAX TOW as the normal -400s.

[747FOCAL]

I checked and now change my opinion. The photo is most probably real. :) Things must be really bad at Air Canada. :(

Somebody might want to point out to Air Canada that there is no 90 day rule in the EU like there is in the USA for not being in complience with the noise certification of an aircraft. Flying without the winglet would be a violation and could get the aircraft grounded. :{

[Hand Solo]

I'm confident the picture is genuine as I saw an AC 744 at LHR last week missing the same winglet. Not the same day as that photo though.

747FOCAL - do you really think a missing winglet is going to make that much difference to the noise certification of an aircraft the size of a 744?

[Onan the Clumsy]

there is no performance penalty when it is missing Then why have 'em?

Winglets :yuk:

[L337]

... because they are a marketing ploy.

[PA-28-180]

Just curious, but wouldn't having only one winglet cause a yawing movement into the remaining winglet? Why leave only one? I could understand a short period of time due to maintenance time constraints, however it seems to be ongoing as per previous post.
Thanks.

[QAVION]

I believe most 747-400 airlines have this in the their MEL/DDG's (or, rather, their CDL's.. Configuration Deviation Lists).

"Remarks and Exceptions:
1. One may be missing
2. With missing Winglet, reduce the performance and structurally limited weights by:

Takeoff and Landing - 9435Kg
Enroute Climb - 4536Kg"

A marketing ploy further disguised with a weight penalty? Cynic I am, but not that cynical.

Regards.
Q.

[Dan Winterland]

The -300 has the same wing as the 1 and 200 series. The -400 has another 11' of wing span over the Classic in addition to the winglets. There are also other aerodynamic and structural differences.

The burn on a -400 is on average 16% less burn than a Classic. Some of this will be down to the engines, but most aerodynamic. I think the winglets are more than just a marketing ploy.

[yakker]

Check out the following for an insight to winglets

http://www.airandspacemagazine.com/ASM/Mag/Index/2001/AS/htww.html

[Compass Call]

A Gulf Air Airbus A340 was seen at Muscat minus a winglet several years ago. It was still minus the same winglet some weeks later and flying around quite happily. So maybe winglets are a marketing ploy for Airbus as well as Boeing.


CC

[747FOCAL]

Hand Solo,

Without boring everybody with a lesson in noise certification......

On any aircraft a winglet of this design equates to a certain amount of wing area. I think the majority of us know this. :E When you remove the winglet you are removing wing area thus reducing lift. You also create an asymmetrical condition. Both of these would require an increase in thrust on approach. You also will not climb as good on takeoff. The 20,000 lbs penalty on takeoff is just one indicator of the level of performance reduction caused by dispatch minus the winglet. The worse the low speed performance, the higher the noise levels. :mad:

If the operation is being conducted in the USA or Canada this is no big problem as the operator can operate out of compliance with the configuration of the noise certification for 90 days. The EU, however, does not make allowance for 90 days or any period of time for that matter.:hmm:

Now having said that, it would have been a real cheap shot to have it become an issue for them on this topic.
:ouch:

[QAVION]

British Airways' CDL's also mentions a 2.5% fuel penalty for a missing winglet.

I think the conspiracy theorists are losing ground here ;)

Q.

[Seloco]

The A319 operating BA967 from HAM to LHR last night was missing its starboard winglet: the end of the wing appeared to be neatly capped off in 320-100 style.

Is there a 'bus expert out there that can advise as to what the performance implications are of such an asymmetric condition (apart from making lefthand turns marginally easier, that is!)?

Presumably these things have to be removed occasionally for damage repair, rather than just dropping off wholesale.....