After giving advice, i found myself in a forced auto situation,
i was practicing for the Nationals later this year, i was doing a SPLIT S, and as i rolled inverted the the engine went lean and died,
i was at this time inverted with forward speed downwind and in idle 2.
Like Paul said , i all i was concerned about was getting it to the ground in one piece.
And i am happy to say all the lessons and training paid off, i rolld out and then dropped the pitch to half stick, turned it around so it was nose in, dropped the stick further and just kept the hellie level, as i had killed all forward speed rolling out and turning into wind, as i was nose in i noticed the wind was blowing it towards a tree (wind at this time blowing accross the disk from NW to SE), so i bottomed my stick and at about head height i gradually added collective whilst rasing the nose trying to get any breeze to speed up the blades, i landed perfectly nose in, which wasnt bad consdering i was over 100 feet away.!!
Negative in itself doest not speed up the blades, it is the angle of attack and forward speed which does, you can have full negative and if you are downwind the blades can still stall.
An Auto was explained to me this way by a full size pilot,
"an ice skater when they come to end of their routine normally end in a spin, what do they do to spin faster ? they move their arms higher above their waste until they meet above thier head, as they do they spin faster and faster" how is it accomplished? they alter the centre of gravity their arms cone in effect, which allows them to spin faster"
the same happens in a hellie, you need a certain amount of forward speed, as you enter the AUTO, you bottom your stick, with the nose slightly down you keep the helli level carfully balancing the cyclic to keep the disk level, as you apprach 1 meter above head height, lift the nose and add just tiny amounf of collective, this will slow your approach, and as you lift the nose further, like the ice skater the blades will spin faster, you then use this enegergy wisely, which is why timing is essential or you run out of head speed,
as you reach head height lift the nose a little more now start feeding in collective, as you drop further to waste height add mor collective and the hellie will start to land, keep adding collective until full stick, it wont matter at this time,, as you should only be a foot off the ground.
as you are tipping the nose upwards you are altering the centre of gravity and altering the angle of attack, the blades are coning, if you was to take a photo of the hellie blades, they would not be level they would be curling upwards like the letter Y, this is called coning. there is more to it than that but i would be waffling without true understanding.
The key to being successful is entering it correctly and feeding in pitch at the right time AND DONT PANNICK!!, it does take practice, but once masterd itis great fun, i always do a couple of autos as i near the end of each tank, so when i really have to like i did yesterday i can keep calm and fly it to the ground.
i would suggest you do a web search on CONING, and Vortex rings, it explains in real depth what is happening you AUTO, if you can get someone to demo it for you. it does help
this was the way i was taught, it may not be 100% correct, but i am not a mechanically minded person so it had to be explained to me simply!
All The Best