A340 winglet!

[makeapullup]

Just a quick question. Can an A340 fly with a damaged/hastily repaired winglet?

Maybe a MKA guy could answer!

Cheers:ok:

[Q4NVS]

AFAIK on the 747-400 this is allowed, but with certain performance considerations et al.

If this is the case, I "assume" that similar would apply to A340.

Only speculating though, thus waiting to hear the "informed" answer.

:ok:

[ANVAK]

Another question: Can a 747 freighter fly with damage to the tail/rudder area?
By the way, on the radio there were some immediate recriminations with ATC (Ground) ensuring that everyone knew what her clearance was..... and the A340 crew not committing and complaining about not being able to make the required t/way. Its going to be an interesting insurance claim.:hmm:

[nugpot]

By the way, on the radio there were some immediate recriminations with ATC (Ground) ensuring that everyone knew what her clearance was..... and the A340 crew not committing and complaining about not being able to make the required t/way. Its going to be an interesting insurance claim.:hmm:

Could you let the uninformed know what happened?

[Romeo E.T.]

SA272 JNB-CDG. Happened during the pushback, winglet sliced thru the tailplane and APU of MK freighters B747 at ORTIA on Monday evening at about 22H00B

[makeapullup]

Happened during the pushback

Was it on the pushback? or was the 747 a little out of the bay to access the front for loading. This with the ATC's knowledge and consent, also a new plan made for the A340.

Will see what happens.

MK B747 still parked there today.

Cheers

[Shockwave Sam]

Just a thought but doesn't it only become an ATC isssue when the aircraft is on the taxiway and an ACSA problem when its still in the bay-we had a similar thing some years ago and were told ATC had nothing to do with us as we weren't on the taxiway.http://www.pprune.org/forums/images/infopop/icons/icon5.gif

[radioexcel]

Saw Lufthansa flying into Cape Town with a B744 about 6-7 years ago with no right winglet and on asking the Capt..he replied "it makes no difference" So I wonder why they have winglets??:sad:

[south coast]

From what I understand regarding winglets, they are neither proven to be more efficeint or economical than if without, except for at a particular level and cruise set up.

So, again, from what I understand, at that particular cruise level and conditions they make the aircraft more efficeint and economical, but perhaps decrease those values getting to that level.

Hence, neither one way or the other.

If you stick something onto a plane and into the airflow you will 1. increase the weight of the total plane and 2. increase the drag, thats about my level of understanding.

[south coast]

Really doesnt matter warlock, anything in an airflow creates drag....!

What you have to decide is whether the penalty is greater or less than the advantage gained while in the cruise?

[tired]

SC- what you're forgetting is that winglets are there to eliminate (or at least substanially reduce) wingtip vortices caused by air flowing around the edge of the wing from the high pressure area beneath to the lower pressure area on top. Sure, sticking something into the airflow will increase drag, but in this case the increase in drag is more than cancelled out by the decrease in drag caused by the reduction of the wingtip vortices - in all stages of flight.

Warlock's quote above from the MEL - "increase fuel consumption by 1%" - says it all.

t

[south coast]

Yes, you are quite right about wing tip vortices, but you have also added weight to the overall aircraft weight, so therefore more thrust is required to push it along, which means more fuel, which in turn means more weight again, more weight requires more lift, which increases the amount of induced drag...

My point about winglets, is there are definately two schools of thought on them, from what I have read in articles, and I think this is proven by virtue of the fact that not all planes have them, eg. 747-400´, b737-7/800 yes, all the Airbus 320 family no, A340 yes, B757,767,777 no.

Explain that ?

[ERASER]

SC – All the Airbuses (310/318/319/320/321) were fitted with winglets, much smaller than the A340 winglets, looks like a delta wing on the tips. Some of the new A320 winglets look like the A340 winglets and even old B727 (private jets) get to be fitted with winglets. The B773 got some funny wing / winglet on the tip of the wing, but I don’t know if it’s a wing tip or winglet.

Seems as if the manufacturers do believe it makes a difference in a/c performance.

E

[south coast]

Eraser...

you are right about the a-320 family, but i was not considering them as winglets, i mean, to be fair, they are something quite different to what the b737 & 747 and a340 have.

this is exactly my point, the weight and size of the 'winglets' that airbus use on the a320 family is far less than that of the b737's, and are obviously deemed to do as good a job, so why the huge things on the b737?

[Romeo E.T.]

The MK plane was parked like that because they were loading freight through the nose. The SAA plane was instructed to push back far enough to exit via the HOTEL exit, which he acknowledged, and again on taxi, was told to exit via HOTEL, which the acknowledged again, and still taxied straight ahead and struck the MK plane causing damage to the APU door and one of the elevators

The SAA flight was delayed by 12 hours because no spare planes were available. It has since been patched up and is flying with one winglet. The MK plane is still on the apron, only departing tonight, nearly a week after the incident.

From the AVCOM forum on the same topic....

[flyboyike]

Eraser...

you are right about the a-320 family, but i was not considering them as winglets, i mean, to be fair, they are something quite different to what the b737 & 747 and a340 have.

this is exactly my point, the weight and size of the 'winglets' that airbus use on the a320 family is far less than that of the b737's, and are obviously deemed to do as good a job, so why the huge things on the b737?

Actually, the "huge" winglets are now available on the A320 family as well, so Airbus must also think there's something to them.

[journeyman]

Okay south coast, you're right - I have it on good authority that the eminently qualified aeronautical engineers and designers at Airbus and Boeing just decided to shove winglets on some of their aircraft as a bit of a lark - much like the guys used to do with the rear wing on a '79 Ford Cortina.
It's all a sales gimmick. Please don't tell anybody.

[Q4NVS]

For an A340-300
Winglet:
One may be missing provided hole is covered.
Increase fuel consumption by 1%.
Increase take off and approach climb limiting weight by 2%.
Reduce 1 engine inop ceiling by 250'.
Max take off weight must not be higher than 260 tons.

What is the MTOW of an SAA A340-300 (2 Winglets)?

Yes, you are quite right about wing tip vortices, but you have also added weight to the overall aircraft weight...

The point being SC, that even if the MTOW is only increased by 2 Tons with 2 Winglets installed and assuming these Winglets do not tip the scale at 1 Ton each (ouch), then it IS worthwhile...:E

Considering these winglets are semi-composite i.e. Lightweight.

More Tons = More $$$'s Revenue

http://www.pprune.org/forums/showthread.php?t=248914

[Haaan]

MTOW for A340-300 is 275000 kg's

[Q4NVS]

MTOW for A340-300 is 275000 kg's

Aah Thanks!

Thus SC, if my maths don't fail me, that equates to 15 Tons "Revenue" per Winglet...:cool:

[south coast]

Q4NVS...

You are way too smart for me...

[Mode7]

Actually, the "huge" winglets are now available on the A320 family as well, so Airbus must also think there's something to them.

Airbus have pulled those large winglets off the A320 for whatever reason resently

[jackbauer]

Not a sales gimmick at all. The winglets have a fuel saving function and more important it reduces the wake turbulance signature of the aircraft. This allows ATC to reduce separation on approach. PS the MTOW for the A340-313 is 275000kg but the A340-312 is 260000kg (smaller engines)

[MarkD]

The design of the entire wing influences the nature of the winglet required, which is why 737NGs and 757s whose wings were designed initially without winglets have the big verticals but on 777s the vortex reduction is dealt with by the raked wingtips.

[Avi8tor]

I had a LONG chat to the 'boys in brazil' on this subject. It started when i asked why CRJ's have them and ERJ's dont. Short answer was that the added weight , cost and complexity didn't justify the small reduction in fuel flow (Anti ice system for these things can be a bitch). For flights LESS than 7 hrs, they are not viable.

I also remember a discussion at SAA on the 744 that lost 1 winglet. The Boeing CDL also gave increased fuel flow and reduced MTOW. However on landing, the trip was sent off to SITA and they reported the aircraft had shown NO DIFFERENCE in fuel burn. However, cause the aircraft in question was Lufthansa, this is a 2nd hand story.

I remember chatting to a 738 captain when half the fleet had winglets and half didnt. He said that the trip fuel was the same for those with and those without. But again, largely used on short haul trips.

A few months later, on seeing the Legacy, i called EMBRAER again and asked if they were about to say sorry for changing there minds. And when the retro fit kit would be out for the ERJ135.

Answer was that NO retro fit. Not worth the effort, and that on the Legacy, they were fitted as most costumers THOUGHT that they were a cool fuel saving idea. ERGO the buyers wanted 'go faster strips'. So they fitted them, even though the benifit was marginal over the aircraft's mission profile.

[south coast]

So the debate continues...

This was my initial point, neither 100% proven one way or the other...the placebo effect, if you are told they will save you fuel then you believe it.

[Balmy]

Dont know if it is related or not but I flew Perth - ORT on 3rd in SAA 340-200 with only one winglet. If I recollect correctly the lefthand winglet was AWOL and looked like some not too permanent repairs.....had me wondering some???:hmm:

[Amateur Turbines]

This brings up an interesting fact about Aircraft design. People think that airplanes are cool. Airplanes hence should look cool and if there is a benefit of cost savings then have at it. BTW wing tip devices have been touted as creating 3.5-5.5% less drag than wings without.

The T-tail design was touted also as a "cool looking" design feature that in my opinion has more faults than merits.

[MarkD]

south coast - Michael O'Leary is not only buying every new FR 738 with winglets but is refitting every 738 he's got with them. MOL doesn't pay for anything he doesn't need - he won't pay for things he should pay for - especially when you consider that the acquistion, refit and downtime probably costs $1m for the in-service frames.

Winglets save more fuel the longer the sector goes, the amount depending on the type of winglet. The tipping point has come now that FR is moving away from the short to the medium hop sector (south of Spain, south of Italy, eastern Europe, Finland etc.) and $62 oil is also a factor. It's not "not proven", it is either appropriate or inappropriate for a given aircraft depending on the usage/sector length. Even on short hops winglets can reduce runway requirements although they may also impact crosswind limits negatively.

Good enough for you?

Have a look on Aviation Partners Boeing's website - they make the "placebos" refits for Hawker XPs, 737s, 757s and probably 763ERs down the road - they discuss the rationale for them there.