if you dont react quick, the rotation speed will be very high very soon.
As a front seat passenger in a US Army Huey (I was a Chinook Pilot) on a free ride to Saigon for a bit of R and R....I had the occasion to participate in one of these events.
At first, I thought the guy flying was making a right hand pedal turn to look for a parking place....as the rotation was quite mild as the Tail Rotor wound down. The first full revolution as we passed what I considered our entry point heading was not too bad but was gaining in rate. As we went by the second time...the rate was very significant and noticeably increasing at a faster rate than the on the first trip around the mast. I had now tweaked to it being a for real problem and not the doing of the Dunderhead who was driving.
As I was a passenger and not part of the crew I was deferring to his Duty Status but began to suggest a course of action....by clearly stating over the Intercom..."Chop the Throttle!".
He did not...and we started around yet another time and on the third time past the starting point....things were becoming a blur...and my suggestion to chop the Throttle was now an emphatic plea!
As we went around on the fourth rotation...my Aviator Ray Bans were leaving my face propelled by my bulging eyeballs...and I elected to take matters into my own hands and chopped the throttle myself.
We were still rotating but at a much reduced and slowing rate...things were coming into focus again...and eyeballs were returning to what seemed a normal position.
I suppose I could have helped with the Collective Pull but then he was signed for the aircraft and was at the controls and one would think he would just instinctively do what was necessary at this point. I was wrong...he did not...and the Skids nicely cushioned our Landing and at the same time made it much easier to get out of the Cockpit as there was no need to climb down but rather to step up just a short bit.
I thanked him for the Ride....and lied when I said I would look forward to a return flight with him in a few Days.
Long story....but should help to describe how quickly things happen when the Tail Rotor decides to take a Holiday.
Getting the power off is the key. Get that right and the rest is pretty much an after thought. Don't and you are in for the ride of you Life that even Disneyworld cannot beat.