As a helicopter pilot I can tell you it is one of the most nerve-wracking missions to be on. Any hovering over snow is made difficult by blowing snow hampering visibility and ruining any point of reference. Even if the snow is not blowing it is hard to hover precisely because of the lack of terrain definition, you can tell if you are moving forward, backward or sideways. Even with a radar altimeter it is difficult, you learn to rely on your crew chief since he can lean out and get a better view. Not a fun mission.
In the same speech McArthur said:
"The soldier who is called on to give his life for his country is the noblest development of mankind."