Unknown military aircraft over wilderness in ManitobaDuring a canoeing trip in the back country of Manitoba, a friend and I decided to stay awake for the Aurora Borealis. We were sitting on the edge of a lake, looking across the water in complete silence. There was no wind, no moon, and the sky was crystal clear. (we were both completely sober) An aircraft suddenly approached us from the left at subsonic speed (we heard it approach) and trailed off to the left at high speed. It was loud and distinct. We tracked the movement of the sound with our heads, but saw nothing. It passed by right in front of us without a visual blemish on the starlit sky. Most unusual was the noise: Two noises actually. One was the sound of a spinning rotor with a gentle swoosh of a ceiling fan, not a chopping or clapping helicopter-type noise. The other, more subtle noise was that of polished metal grinding against metal with only slight friction. But that was it, no sound of a engine, powerplant, propwash, or any sound usually associated with known aircraft. My friend and I were stunned, both of us had the same reaction to and recollection of the event. We are both atheists, do not believe in ghosts, superstitions, or ET's. I believe that we witnessed a man-made aircraft of unknown origin using unknown technology. There may not have been other people within miles of our location, but there is a hope others in the area had a similar experience.((NUFORC Note: The sound reported is not dissimilar to sounds reported to us that appear to be associated with bona fide sightings of UFO's. However, the sound could also have emanated from a military aircraft, designed for almost silent flight. Military units dedicated to "Special Operations" are thought to possess helicopters, for example, that are much quieter in flight than typical helicopters. PD))