On Sunday, December 20, 2020 at 1:43:57 AM UTC-5, wrote:
Grand Teton is 13,776 ft. Icefloe Lake is 10,652 ft. If the first frame began at release altitude then they were slightly below and to the south of the summit of Grand Teton. In 3:09 they lost 3100 feet give or take.


https://www.youtube.com/watch?v=lvWNkP-NzAQ

The saddle of the ridgeline level with the glider Figure 7, time stamp 3:06, is 11,500. It doesn't look like there was any altitude loss to speak of, and perhaps a small gain between 2:57 and 3:06.

If a spin event happened shortly after 3:06, it may not have happened like in the linked video. When stalled in a full rudder over slipping turn of 30 degrees bank, the L-23 spins into the low wing, -against- the rudder. The entry looks similar to Figure 7 (but desirably without rocks). In that case, expect an excursion to 60 degrees nose low pitch, about 180 degrees of (slow) auto rotation before recovery and a few hundred feet of altitude lost. I have done many times with students as a part of a lesson on slips and slipping turns.

T8