Doug Riley said:
No reason why a Little Wing wouldn't fare just as well.
No disrespect to Ron's excellent design and well-built frames, but I think he'll agree that it's built a lot lighter than a proper Cub. However, that built-lighter has the dual effects of lowering strength, but also lowering mass... Ron is one of the guys who really thought hard and long about safety before he started cutting metal.
Much, much more could be done with the frames of pusher gyros, too.
Right, we can do better. To be fair to the designers of pushers, they've worked on other safety issues but have not addressed crashworthiness
per se. After all, most of the crashes caused by PIO and PPO generate deceleration forces that are not survivable, full stop.
So of course crashworthiness is a facet of the design that hasn't been Job One. Still, it matters. Consider how much less serious Jamie's injuries might have been if the Marchetti he was in had been designed with a view to crash survival. He was racked up pretty good, from what was self-evidently a survivable (but still pretty violent) crash.
Even so, 4130 is a tougher material than aluminum alloy. "Toughness" in this sense refers to the ability of the material to absorb energy AFTER the load on it reaches the permanent-bending level.
It's a characteristic of most ferrous metals that there is a big range between the plastic yield point (where it bends) and the failure point (where it lets go). For mild steel, this is probably forty or fifty percent of the range. It's a characteristic of most aluminium alloys that they have scarcely any "plastic range". Also, aluminium is subject to fatigue much more than steel is.
Corrosion resistance is about a wash between the two. Pure aluminium is quite resistant, but common structural alloys are not. That's why aluminium sheet is customarily finished with a thin coat of elemental aluminium (that's what "AlClad" means).
I have wondered about Titanium alloy tubing as a possible construction material. You get the weight of aluminium (near enough) but the strength of steel, and it has an almost ferrous-metal-like plastic range: nice and wide. But it is costly and a bear to work.
David Holmes said:
Sorry, David and guys, technical term for "bleeding out." Below a certain blood pressure and volume (which will vary by individual), the organism cannot sustain life because not enough O2 is passing by the cells that need it. The organism is smart and involuntarily shuts down first the peripheries (through peripheral vasoconstriction) and then more and more of the other systems. Consciousness goes quite a ways before life does. They say it's not that bad a way to go, but then again no one who ever said that went all the way (obviously).
With modern trauma medicine and emergency medical transportation, this is increasingly rare. Still happens in some air crashes, though.
Yeah, animals can be slaughtered by bleeding them out, and in some cultures have to be (it's part of Kosher and Halal butchery, for example).
cheers
-=K=-