I'm looking for an older film in which a plane carrying people goes down in a deserted desert environment. They are living in a cave and the encampment is regulary attacked by orangutans or Baboons. They are picked off one by one by these animals. At the end of the movie, i think there is a rescue and 1 person is left behind to his fate. Do you know the name of this movie? Thanks

Congo? either that or Kickboxer 24: This Time it's Primal

The sands of Khilahari(or something like that)

I was able to find the movie with your clue. It is titled
"In the Shadow of Kilimanjaro (1986)".