Several people have replied to this pic.. I say, "Amateurs ALL!!!!"
First of all, that is not a proper "glider." You could stand up on a proper glider and on a proper glider, there'd be no plastic schit and in the 70's, there'd DEFINITELY be NO pink schit.
On a proper glider, one could stand while facing the end of the swing set while rocking it back and forth to maximum glide. One could then take turns doing that while ones friends stood back and threw dirt clods at said glider. A dirt clod might even (unintentionally) have a rock in it and strike said glider just above the eye brow. Said glider might have then had to take one of many trips to the ER to get stitches for yet another neighborhood mishap.
Today, such a story would lead to many, many questions by the ER staff and removal of said child from the home. In the 70's, one would be back out on that glider 20 minutes after returning from the ER!