ShyT
There's a smart one in every family! Definitely a grey hair moment, now fixed!!
The S55/Whirlwind was great to demonstrate VRS. As you applied a little power the helicopter would shake & go into VRS ( that's if the other factors are present ) The ROD would settle about 3000 ft/MIN, apply lots more power, then the shake would increase & the ROD could get up to 6000 ft/MIN. Remove all power & out she comes, get some airspeed & climb away if required.