Fareastdriver:
At the FOB at Bessbrook in the mid 70s a loaded Puma approached the LZ. There was a Scout and a Sioux rotors running on the small pads in front of the main pad the Puma was going for. IA with SOPs the Puma transmitted his arrival for the benefit of the two helis burning and turning.
The Puma landed. The Sioux exited stage left upside down and a frantic army pilot entered stage right from the Ops hut.
I suppose there may be many(?) of these anecdotal stories about small helicopters being flipped over by big helicopters. In the above-mentioned case of The Puma And The Sioux, I doubt that the Sioux driver could have done anything even if he had been at the controls...other than roll it up to 3100 and fly away before the Puma got there.
Teetering systems have no...as in ZERO...control power when the skids are on the ground. This applies whether the MR rpm is at idle or full. Doesn't matter what you do with the cyclic. For the cyclic to "work" the helicopter has to be in the air. And even then, cyclics in teetering helicopters have little control power as Nick, Shawn et.al. have constantly explained.
The Sioux was likely more downwind of the Puma than the Scout, I'd say, and at least the pilot was not along for the ride to possibly be injured.
I've flown just about my entire career in two-bladed systems. In 10,000 hours-plus, this is my experience: Sitting at idle, I've had all kinds of helicopters come in and park next to me, and I've had all kinds of weird wind gusts impact on the helicopter. Never...and I do mean *NEVER* have I had to actually do anything with the cyclic. Oh, sometimes the ship will shudder and shake and slide around a bit, causing me to throw the clipboard up in the air and grab the sticks in panic - not that there was anything I had to (or could) do. Never have I had to move the cyclic in response to a "sudden gust" of wind.
If the cyclic stays centered, then it will *ALWAYS* bring the rotor back to that trim position within a blade or two - it can't help it.
Now, let's talk about the sustained downwash from a big ship landing immediately adjacent and upwind. I reckon that if a Puma landed so close to me as to blow my helicopter over, then it's his fault for landing too close and MY fault for not realizing that he's a dumba** and getting out of there when I had the chance...or stopping the rotor and securing the blade/ship.
At PHI, we had to tie the *aircraft* down to the platform with big straps if a medium (e.g. 412) was to land beside us. But we could not even be on the deck, tied-down or not, even if there was room, if a "big ship" (Puma, 214ST) landed.
To sum up, at idle there is not a lot you can do. If the gust is small and brief enough to cause a rotor divergence, the cyclic will bring it back (if the cyclic has been properly frictioned, of course). If the gust/upset is so large that it moves the helicopter, the hapless pilot is just along for the ride. Good luck getting it spooled up to 100% before it falls over. At that point, the only thing the pilot is good for is securing the engine, fuel valve and master switch.
I don't know what happened with the most recent case where the *pilot* of the 407 got whacked and killed by the MR blade. I'm baffled at the sequence of events that lead up to that mess. How could that pilot have left the disk so low in the front?? When I'm "hot-loading" in my 206, which I do quite often in my operation, I pull the cyclic almost all the way right-rear. (I know that the blades won't hit the tailboom even at full aft cyclic.) If I get out of the ship while it's running (and sometimes I do - horrors!), I make sure that the cyclic is centered laterally and aft of center longitudinally (given the 206's forward mast tilt) to get the disk way up in front.
This whole thread would be needless if pilots would just exercise some common sense once in a while. Unfortunately, as we see all too often in our industry, pilots do not come so-equipped.
I keep in mind the amusing image of the lone S-76 pilot in Los Angeles, California a couple of years ago who got out of his big Sikorsky (without anyone else in the cockpit) to check a door while it was running at 100%, only to have the dang thing try to take off without him. Now *there* was a Real Man Of Genius! One can only imagine how the ensuing phone call to the Chief Pilot went, but it must have been hilarious.