In the movie "Lawrence of Arabia", in one scene a man was completely submerged in desert quicksand. Is this really possible with dry sand or does it just happen in Hollywood?

Dry quicksand has only been produced in lab conditions. Fine grain sand with a flow of air running through it produces sand that will hold no weight.
It can theoretically exist in nature, but has never been documented.

http://www.thetartan.org/2006/11/20/scitech/htw

There would be little chance of finding quicksand in the desert as in the movie Lawrence of Arabia. The desert is just too dry.

http://digicoll.library.wisc.edu/cgi-bin/UW/UW-idx?type=turn&entity=UW.WIEv101no3.p0013&id=UW.WIEv101no3&isize=text






engr.wisc.edu/wiscengr/issues/apr97/quicksand.html no longer exists

It is possible to be engulfed by sand if there's been a strong wind and you're trying to climb up the wrong side of an unstable dune - but that's not quicksand, that's a form of avalanche. Quicksand is rather more a beach or river based phenomenon - plenty of water. (Baloo grew up and still lives in very sandy country but has never yet met a quicksand that's worthy of the name.) https://en.wikipedia.org/wiki/Quicksand

I did a bit of research myself and it appears that the jury is still out on the subject of dry quicksand. There are stories of whole caravans being lost without a trace and vehicles have disappeared in deserts. The conditions may exist in nature but have never been documented.

https://en.wikipedia.org/wiki/Dry_quicksand