Floating like a butterfly on planes - the "Ground Effect"
 

Moderator note: This thread originated in the BA forum, then was subsequently relocated to the TravelBuzz forum. /JY1024, TravelBuzz co-mod


In this month's National Geographic interview with a butterfly expert, it says:

Has anybody experienced this on a BA plane? I cannot say that I have, but I will see if I notice it on my flight to FRA tomorrow.

I was on an AA from TPA to CLT that felt like this and there was a communal intake of breath when it felt like the plane wasn't going to touch down when we were a couple of feet off the ground.

I'm not sure it's a BA thing TBH.

A regular (i.e. Every flight) occurrence, if it is what I think it is...

I believe it refers to that split second when you feel you should be on the ground but wheels haven't touched Tarmac

This occurs in helicopters and on fixed wing aircraft and is not specific to BA.

Nothing to do with BA, it’s just aerodynamics.

When a fixed wing aircraft gets close to the ground (less than a winglength - maybe about a quarter winglength for a noticible effect) then additional lift is generated from the uplift of air passing under the wing. At this time it’s possible for the plane to fly at slightly lower airspeed than would be normally required to maintain lift.

Ground effect happens on take off as well as landing, it’s not as noticible though on take off (unless you’re the pilot and try to rotate before you’re at the right airspeed!).

This effect is sometimes used in actual water skimming craft.

This is an aerodynamic effect, but only one of many things that provide the forces on an aircraft. A pilot that neglects to flare will slam into the tarmac - ground effect isn't going to stop you. And saying that any floating effect you feel is directly/solely due to ground effect is way oversimplifying the many parameters.

Plenty of small-scale Wing in Ground Effect aircraft have been built - https://www.youtube.com/watch?v=svvfzETPmNg - and there have been proposed large scale adoption for aircraft the size of today's jets, though I don't see it happening.

I've certainly never felt it on an FR 738. It feels like their pilots are told to land very firmly!

Then you should have looked at bit closer, and you might have discovered the 'Ekranoplanes'. They were essentially Soviet Navy missile destroyers, but moving a lot faster burning a lot more fuel.

http://i65.tinypic.com/sfbadl.jpg

The trick about WIG aircraft is, that you need less wing to generate the necessary lift as you're flying in the ground effect, and that wing is able to carry an obscene amount of weight. On the other hand, your fuel burn is astronomical as you're ploughing your way through the thick air near the surface.

I'm confused about the reference to BA?

I'd say it's impossible for a pax to tell apart adjusting flight controls or ground effects from the back.

Me too. Considering the reputation for rudeness on these forums, I'd say the group has been pretty good about skimming over such an odd reference.

Here's more than you'd ever want to know about ground effect.

https://en.wikipedia.org/wiki/Ground..._(aerodynamics)

I am guessing that this may have (briefly) be posted in the BA forum and been moved.

This is a very well known aerodynamic effect and one that Concorde wing designers perfected and harnessed to be able to land so smoothly at high speeds. All achieved long before complex computer modelling allowed wing shapes to be perfected like today.

Not really, it can be felt quite easily when ground effect is in play.