JetEZE crash, Pilot lost

[enginesrus]

All materials I would not care to trust keeping me so high off the ground. Its bad enough thinking about some small bolts taking some huge stresses, I'm just not a composite fan, and for real Styrofoam? Maybe good material for cushioning items in a box for shipping, but there is no tensile or bending nor shear stress capabilities with that material that I know of. And fiberglass? I've seen way to many kenworth size truck hood fender combo's with major cracking in very low stress area's.
Wing separation is a no brainer on that one.

[Kyle Boatright]

All materials I would not care to trust keeping me so high off the ground. Its bad enough thinking about some small bolts taking some huge stresses, I'm just not a composite fan, and for real Styrofoam? Maybe good material for cushioning items in a box for shipping, but there is no tensile or bending nor shear stress capabilities with that material that I know of. And fiberglass? I've seen way to many kenworth size truck hood fender combo's with major cracking in very low stress area's.
Wing separation is a no brainer on that one.

You realise... Nevermind.

[Marc Zeitlin]

All materials I would not care to trust keeping me so high off the ground...

If you don't know what you're talking about, it's better not to say anything.

[David Lewis]

The foam is just to help mold the skin to the right shape. It does not carry any structural load except to resist oil canning and local buckling, which are all small forces.

[BoKu]

The foam is just to help mold the skin to the right shape. It does not carry any structural load except to resist oil canning and local buckling, which are all small forces.

I don't think that's exactly true. I'm not an engineer, but I'm pretty sure that the foam is indeed loaded in shear as it reacts lift loads out of the skin and into the spar. An engineer like Marc Z. could tell us for sure, and probably exactly how much.

--Bob K.

[Marc Zeitlin]

I don't think that's exactly true. I'm not an engineer, but I'm pretty sure that the foam is indeed loaded in shear as it reacts lift loads out of the skin and into the spar.

Eh, a little bit, but Mr. Lewis is pretty much correct at least in the case of the blue flotation foam used in the wings, canard and winglets of canard aircraft. Mostly, it's there for ease of fabrication (gives shape without a mold) as well as supporting the skin against sheet buckling.

An engineer like Marc Z. could tell us for sure, and probably exactly how much.

Well, if we had an engineer like Marc Z. hiding somewhere around here, maybe he could tell us for sure (and how much), but thankfully, I know of none. Marc Z. himself, however, cannot tell us for sure (or how much) - only what his understanding of the situation is :-). Which is that the actual shear transferred by the foam is a very small percentage of the total, if even measurable.

However, the facts are clear that composite materials (foam, fiberglass, epoxy) are completely capable materials for the construction of both experimental and certificated aircraft, when designed and used appropriately.

[Bob Dingley]

This is the 21st century and composites are in. Boeing is having good luck with the 787. Airbus over in Alabama is doing just fine with the A 320. When the Sikorsky 76 hit the market, I got checked out in the type. (before there even was an "A" model.) The structure forward of the MLG is Kevlar honey comb. Its called the Kevlar Komet. I've seen some of these AC take some horrible hits, flown into the ground or rolled over. They were all put back in service. There are at least 3 nations that use these as combat aircraft. No problem with structures. Our civilian models got hydraulic and electrical upgrades however from lessons learned in the military ops. This type weighs in lighter than semi monococ aircraft, but a lot tougher. And they don't corrode.

I'm glad to see that several posters to this thread are looking at aileron flutter. If that turns out to be the cause, it doesn't matter how much you up grade the hardware or even make the wings of plate steel.

Bob

[martymayes]

All materials I would not care to trust keeping me so high off the ground. Its bad enough thinking about some small bolts taking some huge stresses, I'm just not a composite fan, and for real Styrofoam? Maybe good material for cushioning items in a box for shipping, but there is no tensile or bending nor shear stress capabilities with that material that I know of. And fiberglass? I've seen way to many kenworth size truck hood fender combo's with major cracking in very low stress area's.
Wing separation is a no brainer on that one.

You have heard of SpaceShipOne?

[Bill Greenwood]

Many small boats ,from sailboat to powerboats to kayaks etc are made of fiberglass and they work well, I think they might be a little heavy in thick sizes for airplanes. As for strength, think of the pounding a ski boat takes in normal day of hitting waves and wakes and they dont redily crack. Think of the pounding a surfboard takes and it is often a foam core for shape with glass wraps around it for strength.