F16 wing movements

[fred flange]

Big fan of american chopper here(for my sins)anyway the 2 leading mechanics went up in f16s as part of a program and one of the jets pulled 9g!! the wing seems to move a hell of alot.Is this normal and what sort of force can they take?
i have found the clip here, http://www.casttv.com/shows/american-chopper/junio... go to 33.25 on the search bar to see it.

[Eric Mc]

Most aircarft are designed to have some flex in their wings. You should see the bend on an Airbus A340!

[RizzoTheRat]

Eric Mc said:

You should see the bend on an Airbus A340!

Tested to something like 4 or 5 meters if I remember correctly. On composite gliders you can see the wing bounce up and down through every bit of turbulance, and on a winch launch they bend up a hell of a long way due to the steep angle of attack.

B-52 is the amusing one though, the wing takes off quite a long time before the rest of the aircraft.

[Munter]

If they didn't bend they'd snap.... Always amusing when nervous flyers can see the wing bend, or when they can see "through" it as all the flaps and whatnot are deployed coming in to land.

[tegwin]

If you think thats bad, have you seen the bend on a helicopter blade? Droop when switched off and almighty coning when under load...

[Mr Dave]

Watch the wing bending tests on youtube of the Boeings. Quite impressive really and quite a big bang whne it all lets go.

[DrTre]

I remember reading (maybe incorrectly) a 747 wingtip flexes by up to 8m?

[adam85]

DrTre said:

I remember reading (maybe incorrectly) a 747 wingtip flexes by up to 8m?

Certainly seems that way, as the whole lot disappears from view if you happen to be sitting in the middle rows!

[central]

777 Wing Load Test -

http://www.youtube.com/watch?v=pe9PVaFGl3o&fea...

[speedtwelve]

Next time you're on an airliner with podded engines, 737, Airbus, whatever, you'll see that the engine pylons have quite a bit of flex dialled in as well. Watch those engine pods shimmying from side to side as you fly through turbulence, great for nervous flyers.

[Mojocvh]

I think from memory (on the fatigue rig) the tornado wings go 1 meter at a simulated 9g....

[eccles]

Some aircraft pump the fuel outboard on the wings to stop wing flex during flight to reduce fatigue damage.

[RizzoTheRat]

Also one of the advantages the 707 had over the Comet in the early days of jet transport. Hanging the engines off the wings reduces the bending moment on the wings meaning they can be lighter on the 707 than the Comet, with the engines burried in the wingroot.

[Eric Mc]

Boeing first used this principle on their B-47 boomber. Hard to believe the specification dates from 1943 and it first flew in 1947.

[speedtwelve]

Hard to imagine that 50 years ago there were nuclear-armed B47s standing on alert about a mile away out my living room window. It's a country park now! I live just down the hill from Greenham Common.

[Eric Mc]

Went to quite a few airshows there.

[eccles]

Eric Mc said:

Went to quite a few airshows there.

Same here, was quite a trek from south wales in a battered old Maxi with my dad. I've still got a big packet of photos from the 1983 one.

[Eric Mc]

I used to make special trips from Ireland (1976, 77,79 and 80).

[eccles]

They were the glory days of the airshow scene to me, money seemed no object and aircraft came from all over the world, also in those days you still had quite a number of older aircraft types in service along side the new stuff so had quite a cross section.

[Eric Mc]

Yep - lots of piston power still around - Nord Noratlas, C-118, Lockheed Neptune, Canadair Argus etc.