To the Skydiving crew at my local field. They do a lot of charity jumps and last week took up a fellow who was jumping in aid of the RNIB, Blind himself, he asked how he would know when to pull the ripcord. "You're on a static line so the canopy will open automatically."
"Fine," he said "But how will I know when to bend my legs in order to land?"
"The dog's lead will go slack."