Hi Guys
Here is my Solution for this Achievement.
to Live after a 100 Meter fall you must fall into deep Water (its on the map slightly darker)
to reach 100 Meter you have 2 Option, a Glider or during the Main Story when you fly with Willis to the second Island.
For the Willis Way, after you jump out of the Airplane and you shall used the Wingsuit, dont use the Suit, simple fall down.
The Mission fails but you get the Achievement. You have only 1 Chance to do that, after you used the Wingsuit its over and never came back.
For the Gliderway (which i showed in my Video). Go to the Location from the Video (is one of many).
Use the Glider and fly a way to the darker Water (which is straight forward)
After you reach the Water, release over the X Button the Glider and fall down. Thats all.
Regards