I agree with the Bloke but I should say that someone who feel from a plane in a desert would likely be under several feet of sand withing two months
Yet no one has crossed the dessert for 3 months.
What happened?
Forever.
Edit: Some explanation. He will walk n/2 distance before taking a break. n starts at 16km, so will walk 8 before needing a break. Then he will walk 4km before needing a break. This will continue forever, as the distance he has to travel will always be halved before he needs a rest.