A340-600 dangerously overweight

Apologies for my limited aerodynamics (remembered from the Air Cadets years ago) but surely flying nose down will result in a lower angle of attack (alpha) and therefore less drag.
It will of course result in less lift which could be recoved with more power.

More power meaning a higher fuel burn and less efficiency! 🙂 Airliners tend to cruise with the nose up 2 or 3 degrees as this is generally the most efficient angle of attack for them to fly. That’s as I understand it, anyway!

Paul

…It will of course result in less lift which could be recoved with more power.

Which in turn will increase fuel burn…….

-Dazza

Today’s update on it..

Airbus in talks to resolve A340-600 forward-weight issue
Alan Dron, London (10Apr07, 12:52 GMT, 192 words)

Airbus is in discussions with A340-600 customers over a weight issue at the front of the aircraft that could have an impact on the amount of freight the type carries.

The type has been found to experience additional loading on the nose owing to weight from heavier-than-anticipated customized premium cabin fittings – such as in-flight entertainment and seat-beds – shifting the aircraft’s centre of gravity towards the front of the jet.

Such a shift can affect the profile and lead to increased fuel-burn. An Airbus spokesman says: “Airbus is aware of this issue.”

But while a report in the UK daily The Times suggests that airlines are being advised to reduce the forward freight hold payloads by up to 5t to compensate, the spokesman claims the actual figure is “more like 2t”.

“Airbus has discussed the issue with customers to try to find a solution for the difference in weights from the reference [A340-600] to the airline model,” says the spokesman.

He declines to name the airlines involved. While the report states that some airlines operating the type are considering taking legal action, the spokesman is unaware of any specific threats of legal action.

Source: Air Transport Intelligence news

Apologies for my limited aerodynamics (remembered from the Air Cadets years ago) but surely flying nose down will result in a lower angle of attack (alpha) and therefore less drag.
It will of course result in less lift which could be recoved with more power.

This only affects LH and their own configuration of the A346. I’m not sure how other airlines are affected.

I’m sure that probably absolutely right, especially, as I’ve shown above they operate the most dense seating of my examples airlines in the forward fuselage too. I think this probably just makes a bad situation worse for them.

LH’s problem is that their rear cargo hold is all but completely used up for their lower deck galley, crew rest and toilets. This entire fixture weighs less than a similar volume of cargo.

It leaves LH only around 6500kg to trim out any weight up front. So if they have 6000kg of cargo in the front hold, the 6000kg in the back is not enough to trim it out and keep the CofG in check.
At least thats how I understand it.

This only affects LH and their own configuration of the A346. I’m not sure how other airlines are affected.

What I don’t understand is why this is exclusively the result of new first and business class seating. I accept that the latest seats of this sort are getting heavier and heavier with new technology and luxury being built in but I don’t believe this is enough of an issue for the following reasons:

i) These new seats, being primarly lie-flat, tend to use more room, thereby reducing the number of seats airlines install, either in premium classes, or by reducing the number of economy seats. Either way the extra weight should be partly offset by an overall reduction in seating. If you compare the seating plans suggested by Airbus on their website, with that achieved by airlines you see an interesting comparison. Airbus suggest that between the front and second row of doors, you can typically fit 66 premium seats, whereas Virgin achieve 45, Thai and Cathay achieve 44, SAA carries 42 in this section of the fuselage, Lufthansa is either 54 or 44, whilst Qatar pushes the boat out with an entire 38 seats in this section of the aircraft! (Do you see where this is going, or do I have to do Iberia for you too? [and I’m not doing China Eastern cos it’ll show nothing!!])
ii) The manufacturer presumably designed the aircraft to be fitted in a single class interior throughout, just incase an airline wanted that, so how much space do these super sized seats use that could be used by normal economy seating? If 1 premium seat uses the space of, lets say, 6 economy seats at the front end (based on three rows of 2 seats outboard of the aisle) then a single premium seat, plus passenger, plus baggage would have to weigh more than 6 economy seats, 6 economy passengers and their baggage, and I simply cannot believe this is true, even allowing for the extra baggage allowance of a premium traveller (which isn’t THAT much of a difference). This all leaves aside the fact that premium classes tend to have a lower average load factor. Again, referring to the manufacturers own seating plans shows that they think the aircraft is capable of 71 Economy PLUS 36 premium seats in this section of the aircraft.
iii) Was the aircraft designed without any seat manufacturer or airline input? The trend in premium seating has been clear for some time now, and therefore I cannot believe the aircraft wasn’t designed with this type of seating in mind in the first place.

Basically, I don’t think Airbus would have a leg to stand on if they end up in court, and to be honest its worrying that even MDD could design long fuselage aircraft that didn’t bend!!!:diablo:

But is it cooked spaghetti? Meaning all flexible and not strong
Or is it uncooked spaghetti? Which is brittle, so not really any better!

I had to laugh when some die hard fan boi on A.net insisted this was a Boeing scare article to kick Airbus while they’re down.

The A340-600 is a piece of spaghetti with wings

There is the comment for the people with a fear of flying!!!!!

:p

Not at all.
I’m just munching popcorn and watching it unfold like the rest of us.

Cop out ! 😀 :diablo:

Oh and I think I can confidently predict ‘oor Sandy’ will have a field day on this one ! 😀 😀 😀

Not at all.
I’m just munching popcorn and watching it unfold like the rest of us.

More of a case of more momentum at the front due to the fuselage being so long!!!
Ren’s got it right, create a new first class section at the back, especially for those “larger than life.”

Oh and I think I can confidently predict ‘oor Sandy’ will have a field day on this one ! 😀 😀 😀

I’m sure I watched a recent ‘Discovery’ type documentary that examined the impact obesity was having on aircraft performance and design..?

I’m not suggesting Airbus have failed to take into account the ever expanding waistlines of your average western traveller, but there was some concern that seats were going to have to get wider and aircraft heavier to cope with the ‘lard asses’ that modern times have created…:D

So my advice is to put the chubby A346 passengers up back ! :diablo:

What utter nonsense. The front end heavy? Had these people done a little research to get their facts right before spouting such rubbish, they’d realise I was actually sat over the wing, nowhere near the front. 😀

Paul

Airbus are past masters at passing the buck

So what it all comes down to is a question whether Airbus has given a green light to heavier seats/beds etc in the front of the plane or not?

Shouldn’t be too hard to settle out. There’s got to be documents about this…

Regards,
Cliff