Originally Posted by
Heliplane
When approaching landing sites, I do wonder what effect my (R44) downwash will have on items/debris near where intend to set down. I try to stay away from things like sticks, chopped wood and items that look like they don't weigh much and the most that usually happens is a bit of dry cut grass is kicked up, which I don't worry about too much.
When asking instructors, etc about the risks of objects flying up, I've generally been told that I wouldn't be creating enough downwash for anything serious to lift up and cause a problem.
Does anyone have any further thoughts or experience they can share on this?
One of the videos online shows the cover going straight UP the back wall of the superstructure, arcing over, and coming down on TOP of the rotor disk. A loud bang and seven or eight pieces flying in all directions. Looked like recirculation of the downwash ie along the deck, up the wall and back down through the rotor. We've all felt the turbulance recirculation causes when hovering close to a hangar wall. Just my speculation, but such an UPDRAFT from a heavy B3 (just refueled, 3 POB, luggage), feet from the aft wall of the superstructure, would be very powerful - clearly enough to lift the metal cover in this instance.
PIC is a hero, getting heli off the deck into the drink, on its back. If he hadn't, a dynamic rollover on deck next to a full Jet A1 storage tank and full heli tank would have caused a fire ball. He probably saved the ship and everybody in it. Amazing presence of mind to trigger the floats when already submerged and inverted.