Is was checking out a pilot in the 180HP Super Cub on skis a few weeks back. After I packed a "runway" in the fresh snow for him (which was more than a km long - lots of room!), we did some circuits. He did okay on the new type. As a part of any type training, I train forced approaches to a stop on the surface. So that was next, with a briefing. He mentioned being an instructor, so I looked forward to disciplined skills. They were, but missed the mark pretty badly.
With a briefing, and a 3, 2, 1 count, I gently closed the throttle, and the frozen lake "runway" approached. I had positioned him at the entry into the mid left downwind to our runway. He focused on his training, and what he would train his students - but no way that would have got us near our runway, nor even to a suitable landing area elsewhere. When he thought he was too high, he turned away from our runway to loose altitude - he did! Without my calling an overshoot with power, the plane would not have survived. He seemed rattled.
I tried to figure out what had gone wrong (beyond the obvious 270 degree right turn off the left downwind to base , he's supposed to be able to teach me forced approaches. I said "let me try".
From the same position overhead, I pulled the power in myself. I followed John Farley's advice, and pointed it where I want to crash, and then just not crash it. The "pointing" involved a turn all the way around to align on final. The "not crashing" part suggested that a good slip would get me down, without building up too much speed to dissipate in the flare. It seemed to work, with the fluffing of snow on touchdown being my reward.
My charge seemed stunned, with expressions of amazement that a slipped turn to the the forced approach area below was even possible. We practiced for an hour, and his skills grew rapidly. He's rethinking "gliding" now.
I resist the notion that an aircraft should be flown at "best glide" speed, if "making" the field is not the primary concern. I would rather point it down, and get it to a suitable final approach close by, with certainty, and then rid myself of any un needed speed as a secondary effort. The worst is I carry too much speed over the fence, and go off the far end of my selected "spot". That's much better than not making my selected spot at all, and crashing at an unsuitable place, which was not my selection.
I hope those training forced approaches also train to just get it down, without stretching a cross country to get there, when a suitable place is very nearby. Power off speed management takes on a different form, but also valuable....