Van's Air Force
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RV-14 Drop Testing
- Thread starter salto
- Start date
This video seems to inform a few things about the differences between the taildragger and tricycle gears. First, the main gear for the taildragger seems much stiffer. You can see that by the amount of deflection in the main gear, but also in the temporary wrinkling of the fuselage skin near the lower engine mount bolts when at the lowpoint in the deflection cycle. The tricycle main gear seems to flex much more, but you don't get the same skin wrinkling as in the taildragger configuration. Clearly most of the energy is absorbed in the main gear of the tricycle configuration whereas the energy absorption seems to be shared by the main gear and fuselage frame in the taildragger. Is it my imagination or does it look like there was some permanent deformation in the main gear in the tricycle configuration for the ultimate load test? The gear flexed so much it looked like you would have driven the brake disk into the pavement. Still, all in all the plane seems **** for stout.
Any wrinkling you might have seen has nothing to do with a difference in leg stiffness. It is just that it is totally different points (and types of structure) that the two types of gear are transferring their loads too.
The load the legs absorb and transfer to the structure they are attached to are pretty close to the same for both models if the test is done correctly.
I do not remember whether there was any permanent deformation in the gear legs after the worse case ultimate test, but it doesn't matter.
Remember..... any load capabilities above limit are owned by the engineers. The structure must be able to take loads up to and including limit, over and over, with no damage or deformation. Anything over limit, up to and including ultimate, there can be permanent deformation, just not catastrophic failure (a gear leg can bend, just not totally fail).
In a (very bad) land that induced loads near ultimate, the brake disks very likely would contact the runway/ground.
BTW, if anyone ever does experience a landing that induces Limit loads, the will probably describe the landing as a crash (Meaning it is way worse than what resulted from what people think was their worse landing). So I cant imagine what a landing that induced ultimate loads would be like.......
The load the legs absorb and transfer to the structure they are attached to are pretty close to the same for both models if the test is done correctly.
I do not remember whether there was any permanent deformation in the gear legs after the worse case ultimate test, but it doesn't matter.
Remember..... any load capabilities above limit are owned by the engineers. The structure must be able to take loads up to and including limit, over and over, with no damage or deformation. Anything over limit, up to and including ultimate, there can be permanent deformation, just not catastrophic failure (a gear leg can bend, just not totally fail).
In a (very bad) land that induced loads near ultimate, the brake disks very likely would contact the runway/ground.
BTW, if anyone ever does experience a landing that induces Limit loads, the will probably describe the landing as a crash (Meaning it is way worse than what resulted from what people think was their worse landing). So I cant imagine what a landing that induced ultimate loads would be like.......
