747 wing bending

[two speed prop]

By how much the wing on a fully loaded 747-400 bends upwards on take-off?

Sad question I know but I need to settle an arguement.

[Lan Ding Gere]

I don't know if this cobblers, but I was once told, that the tips of the wings can bend as much as between 6 - 8 feet.

I too would be interested in finding out if I was told a lie.

LDG

[chiglet]

A fully loaded B52....40+ feet
I once watched an Aussie C130 t/o at RAF Kuching, and the wing went from [guessing] 10deg Anhedral to 5+ deg Dihedral. :eek:
I'm NOT a mathamatition,[spelling] so what's the flex?
we aim to please, it keeps the cleaners happy

[Intruder]

IIRC, it's about 10 feet.

One way to gauge it is if you are riding on one with a clear view of the wingtip out the window. On final approach, set your head such that the tip is right at the top of the window, and brace your head so it doesn't move. When the airplane lands, watch how far the tip drops.

On landing the airplane is relatively light, so the bending is not as much as at takeoff. You can do a similar check on takeoff, but it's harder to find a reference near the bottom of the window when on the runway, and watch the tip rise on takeoff.

[wryly smiling]

I was always told 10-12 ft which is not unbelieveable as I've seen a couple of ft deflection just with some fat bloke walking on the wing

[two speed prop]

10 feet sounds about right.

cheers all,

TSP

[noknead]

A B52's wingtip will rise by 17ft from start of the take-off run to rotation. I think I read or was told this somewhere in my dim past. I think "40+" feet is a little off the mark but I am more than happy to be proved wrong.:confused:

[dick badcock]

I think the 40ft referred to for a B-52 are valid in the sense that the wings flexed so much before failure. I too have seen a picture in one of my aerospace structures textbooks of wing bending tests of a B-52. Of course in normal conditions the wings wouldn't bend nearly as much!

[chiglet]

In my "defence" :rolleyes:
I [once] read that a B52 wing "flexed" 'up to 40ft' in turbulence.
Where? Dunno :confused: BUT, if you look at the "droop" [oh DO be quiet missus] pre t/o to the so called "standard" airbourne dihedral, I don't think that it's that far out:D
we aim to please, it keeps the cleaners happy

[expedite_climb]

I once saw a film on destructive testing techniques on an airliners wings where they were bent up to 10m before they snapped.....

[PA38]

Once sat at the light aircraft hold at Manchester (24) and watched the wingtips go up a long way on an American airways 767, before it left the ground.... Well I was impressed:D

[sycamore]

Chiglet
An Albert`s wing is appx. 15ft off the ground,and span is appx.130ft.,so with 10 deg. anhedral on the ground,the tips must have been about 5ft off the ground?? And flexing to +5deg on t/o would give about 15 ft total movement? Don`t think so as I`ve only seen about 3-4 ft flex and that was pulling some!What you may have seen is the fact that Albert has a relatively narrow track u/c and rolls a lot in a x-wind and the wings can move through quite an arc whilst one tries to lift the wing level as it also affects the steering,can feel like a2CV!!;)

[chiglet]

sycamore,
It was at RAF Kuching in 1965, and [I think] it was a C130a with drop tanks. More than a few of us were amazed just how much droop there was, and then the dihedral. I have watched the Saudi Hercs at MAN over the years and not one has had the "range of movement of the one in Borneo
we aim to please, it keeps the cleaners happy

[ETOPS773]

I had this link on my favourites bar,shows the flex quite nicely I think.
re:two speed prop
http://www.airliners.net/open.file/214807/M/
re:PA38
http://www.airliners.net/open.file/271092/M/
And a couple of A330 shots
http://www.airliners.net/open.file/256844/M/
& http://www.airliners.net/open.file/268329/M/

this one isn`t really wing flex related,but I thought its really neat,so here is an interesting link!!!
http://www.airliners.net/open.file/263871/M/& http://www.airliners.net/open.file/251451/M/

[englishal]

dunno, but the winglets are 2m...

Cheers
EA;)

[sycamore]

I`ve sent a private message.;)