Is there any evidence of nosewheel aircraft flipping over on EFATO landings on rough ground, assuming they land more-or-less under control? I would think that the chances are not that big.
The CofG of an aircraft roughly lies in the spar box. Slightly higher in case of a low wing, slightly lower in case of a high wing. And for your typical light aircraft that's approximately 1 meter of the ground. Maybe 1.5 meter in case of a high wing, but let's go with the 1 meter for now.
The point of rotation in this scenario is the place where the nosewheel meets the ground. That's something like 2 meters in front of the CofG.
For the vectors to work out so that the aircraft indeed flips over, with the nosewheel as its rotation point, the nosewheel needs to generate at least approximately 2G in horizontal deceleration. Multiply this by the mass of the aircraft (say one ton), you're talking about at least two tons. (Less in case of a high wing, but still a considerable amount.)
My gut feeling is that if the nosewheel snags on something, the nosewheel assembly simply breaks off. It's nowhere near strong enough to handle something like twice the aircraft mass in the horizontal. The aircraft will then continue to slide on the engine cowling. And that cowling, coincidentally, has more or less the ball shape you were looking for in the first place.
Further supporting my gut feeling: What I've seen so far about water landings in nosewheel aircraft (see for instance the Equipped to Survive site) is that even in a water landing scenario the aircraft will dig in, but in the majority of cases not flip over.
Taildraggers, on the other hand, are a totally different thing. The horizontal distance between their CofG and the rotation point (the mainwheels) is so short that they can sometimes be put on the nose by simply braking too hard.
Last edited by BackPacker; 17th January 2012 at 07:54.