Airbus A380

[alexgv1]

Forget gravity, try the FAA. Maximum allowed size for a regular commercial aircraft is 80m length by 80m wingspan for taxi and manoeuvre purposes. A380 is 78m wide so can't get much more.

In terms of a maximum theoretical size, physics would not be the limit but most likely the powerplant.

[swiftus27]

How else does one deal with gravity/downforce?  You need more lift.  To get it, you need more thrust to generate it, less induced drag, and/or more wing area.  

The other way is to have less "gravity" by lowering weight.
 
Alas, you're right.  Most of this is in the powerplant. At some point, there will be diminishing returns as these fans can only get so big.  

There is such a love affair for this 380

[cht7520]

In terms of a maximum theoretical size, physics would not be the limit but most likely the powerplant.

Imagine sticking 4 GE90-115B engines on the A380...

[swiftus27]

The 773 engine?  With 4 of those on an A380, you could fill the plane with liquid metal and it will still have togo power

[Zabuti]

This is not completely impossible... Airbus is actually working on an improved version of the A380, probably A380-1000. It would be about 750 persons load in "regular seating", but about 1000 is LCC seating.

WOuld probably need powerful engines like B773...

But IMHO, I doubt this project will give birht... A380 is already critically big and the project has been far more costy than expected. I doubt there is a STRONG need for a bigger plane.

[alexgv1]

Yeah I doubt the initially proposed variants A380-900 and A380F will ever surface. The latter especially as FedEx defected to the 777F.

[LemonButt]

The reply at the first page (A390 thingy) made me think about this;

What would be the absolute maximum size of an airplane? I mean, at some point, there must be a limit when the gravity beats the lifting force.

But is there any evidence or research that would answer this question?

Lift, to make it stupid simple, is a function of wing surface area.  Assuming zero improvements in engine power, you would reach a theoretical limit where wingspan/area would reach a point where the wings become too heavy for additional engines to make up for the weight increase.  You could have an aircraft with a wingspan of 1 mile if you had enough engines.

[alexgv1]

I could have some real fun in this thread, just as well I'm on holiday or I'd be having a field day.

[swiftus27]

Lift, to make it stupid simple, is a function of wing surface area.  Assuming zero improvements in engine power, you would reach a theoretical limit where wingspan/area would reach a point where the wings become too heavy for additional engines to make up for the weight increase.  You could have an aircraft with a wingspan of 1 mile if you had enough engines.

The induced drag would be amazing... new wing designs are also becoming popular.  Look at the 787 in flight.   They curve in this amazing way.

[alexgv1]

Look at the 787 in flight.   They curve in this amazing way.

Raked wingtips. Twice the drag reduction of blended winglets on long sectors.

[cht7520]

Raked wingtips. Twice the drag reduction of blended winglets on long sectors.

A bit off-topic...

Does the wingtips/lets affect how a plane performs in big-ish turbulences?

I ask this because personally I notice the A343 doesn't shake as hard as the 77Ws. Or, more like the shaking of the A343 feels a bit 'controlled'. It can't be a coincidence that I get bigger turbulences whenever I'm on a 77W especially when I've been taking both A343 and 77W approx. 3 times each a year for the past 4 years.

[alexgv1]

A bit off-topic...

Does the wingtips/lets affect how a plane performs in big-ish turbulences?

Not particularly. Their side area is too small to even add to lateral stability. FYI B77W has raked wingtips also. A343 has only winglets. Only speculation is that the 340 has larger wingspan so adds stability.

I found personally that there was no more shaky experience than the GE90s on the B77W spooling up for a step climb. Very awesome; you can feel the power.

[cht7520]

Not particularly. Their side area is too small to even add to lateral stability. FYI B77W has raked wingtips also. A343 has only winglets. Only speculation is that the 340 has larger wingspan so adds stability.

I found personally that there was no more shaky experience than the GE90s on the B77W spooling up for a step climb. Very awesome; you can feel the power.

I see. Thanks for clarifying.

With shaky experience, try flying above a monsoon, awesome . I always say to myself 'brace yourself' when I see the plane going towards a wall of cloud at 38,000 feet.

[alexgv1]

I see. Thanks for clarifying.

With shaky experience, try flying above a monsoon, awesome . I always say to myself 'brace yourself' when I see the plane going towards a wall of cloud at 38,000 feet.

You're welcome. Glad to be of some use 

Flying into Hong Kong during a tropical storm was interesting. Did it during the great one of '09 in a 330. Lots of windshear, was a point or two where the plane plummeted. And the RVR was tiny. Barely saw the runway until we were on it. Fun stuff.