On Monday, February 13, 2017 at 10:45:27 PM UTC+3, Jonathan St. Cloud wrote:
Came across a blast from the past on youtube. There was a video of teaching s-turns for glide path control. Looked to be from the 40's. Not sure why they would teach this when a slip would be safer and more effective.

Doesn't have to be one or the other! You can get much more sink rate in a slip if you use more aileron than the rudder can compensate for, and turn as a result.

Slipping full brake S-turns: more sink rate, longer path through the air -- *much* more height lost on the same length final.