It's been discussed to death here and in other places, and the bottom line seems to be simply: if you have enough height you can do it, if not - don't.
One aspect I never see mentioned is this: Assuming you have reached your critical height, from where you have determined, through diligent practice and careful measurements, no doubt, that you can do a 180 degree turn before smiting the earth. The standard drill I always see taught, including my early glider flights, was to pitch down for airspeed and then haul it around, let's say for example to the left. So once you completed your 180 degree turn you're facing back the way you came but the runway is now way over to your left, so you you haul it around some more to complete about 270 degrees to the left and then sharply reverse the turn 90 degrees right and line up with the runway. At which point you're doing pretty serious banking while really close to the ground and about to touch down. Especially in gliders with long wings that always seemed a bit iffy. I know in practice it all gets a little rounded out, but that is essentially it.
My first reaction, which I drilled into myself from flying ultralights, where this sort of thing was not uncommon, was to first turn away from the runway, let's say to the right. Not quite 90 degrees but close. Then reverse the turn, left now, so that when I roll out I am already lined up with the runway and don't need any more yanking and banking near the ground. We're talking about the cropduster's P-turn in essence. The traditional method of turning back is more like a reverse, mirror image P-turn.
Both methods require the exact same height loss to execute, there is no difference in the physics involved.
Comments?
One aspect I never see mentioned is this: Assuming you have reached your critical height, from where you have determined, through diligent practice and careful measurements, no doubt, that you can do a 180 degree turn before smiting the earth. The standard drill I always see taught, including my early glider flights, was to pitch down for airspeed and then haul it around, let's say for example to the left. So once you completed your 180 degree turn you're facing back the way you came but the runway is now way over to your left, so you you haul it around some more to complete about 270 degrees to the left and then sharply reverse the turn 90 degrees right and line up with the runway. At which point you're doing pretty serious banking while really close to the ground and about to touch down. Especially in gliders with long wings that always seemed a bit iffy. I know in practice it all gets a little rounded out, but that is essentially it.
My first reaction, which I drilled into myself from flying ultralights, where this sort of thing was not uncommon, was to first turn away from the runway, let's say to the right. Not quite 90 degrees but close. Then reverse the turn, left now, so that when I roll out I am already lined up with the runway and don't need any more yanking and banking near the ground. We're talking about the cropduster's P-turn in essence. The traditional method of turning back is more like a reverse, mirror image P-turn.
Both methods require the exact same height loss to execute, there is no difference in the physics involved.
Comments?