Factual error: Walter gives the volume of additional air/oxygen from the tank as "298 cubic liters", it is either cubic ft, cubic meters or simply liters, not cubic liters. (00:32:35)
Factual error: They repeatedly say how equipment will freeze in moments, but they leave their faces exposed and coats open, hoods off at times. In such cold temps, the skin would freeze in minutes.
Revealing mistake: When Ralph is talking to the Special Forces Unit, the spectrogram at the bottom of the screen does not match the voices from any characters or the gunshots.
Answer: A propeller sucks in from one side and pushes away from the other side.