I'll say this, several times in my short grunt career I was under landing 46's and 53's. They whip up quite a bit of dust and debris and that's no secrete. That frickin MV-22 seems like a whole different animal.
On one of my visits to Quantico last year I found myself down at the far end of LZ 7 when an Osprey was making his final approach. He was coming in just barely over the trees like in the video above. I was directly under him so I knew I was going to get knocked around a bit by the rotor blast. I had no idea that sucker was going to blow my ass back off the edge of the LZ, down the embankment and thru the woods. Lost a nice Larue baseball cap....
A lot of it may have been not being as young as I used to be but I swear I don't remember the rotor blast from a 56 being anywhere near that powerful.
Next time I stay up by the road with all the other old folks.
Here's the video. I stopped filming when I realized I was going for a little tumble.....