Dripping in sweat and barely able to keep his bloodshot eyes open, a handlebar-moustached Nick Nolte stunned travelers at the Kauai Airport this week -- by passing out cold on the terminal floor!

TMZ obtained these photos taken by one of Nolte's fellow passengers, who told us that the incoherent actor drifted in and out of consciousness on the airport floor for more than two hours Monday night, after their flight was delayed because of engine problems.

According to the source, Nolte was still extremely friendly despite his groggy state -- chatting with fans and allowing passengers to snap photos, however, he wasn't entirely functional. "At one point we helped him put a dollar in the vending machine."