First, the two recent accidents where they chopped the tail, they were possibly training VRS recovery. We don't know this but if they were, what would cause the main rotor to strike the tail. In both recovery methods, the disc is moved either moved forward or laterally. In all my years of flying, I have never heard of a tail strike in either training for VRS or when it happens for real. I have a feeling that in neither case were they training for VRS but if anybody has more insight, I'd like to hear it.

For real, the FW world learned about this years ago.  You can teach spins all day long on many airframe types; some are not recommended.  BUT, some spins can become unrecoverable, so there are limitations on spin training.

Maybe the RW world needs to do the same with VRS training

we've been practicing this for decades without problems. I can understand the flapping thing.

I know when I used to practice it, as soon as the shuddering started, i would initiate a recovery.

just saying

Solution:  We should simply stop practicing landing aircraft.

Full downs have almost become extinct because they caused accidents.

Predictable outcome in an airplane is easier because you are working with a stable platform.  Divergence will exist after a control input but if the condition is neutralized the tendency is to return to last known point of stability.  In a helicopter you are always in a state of  divergence.  The pilot for the most part is the known point of stability without autopilots or stability augmentation systems. 

I don't know if the rotor blades could get to the tailboom in a true state of VRS because the rotor system would be in a positive G configuration.  Extreme aft cyclic and unloading the rotor system at the same time might cause it but that would a totally out of character maneuver for VRS recovery.   

When a rotor system (either tail or main) operates in turbulent (dirty) air, it becomes aerodynamically inefficient. It will work, but just not at the level of efficiency that may be needed at the time.  When demonstrating or practicing SWP, or VRS or whatever the term of the moment is, the minimum intent is to get the pilot to recognize the conditions that are conducive to VRS, AND recognize the initial indications of SWP.

SWP evolves into VRS. You should be taught that the vibrations from the main rotor system are your final warning before entering into VRS and should be thought of as a command from the aircraft to MOVE in any direction.

When a rotor system (either tail or main) operates in turbulent (dirty) air, it becomes aerodynamically inefficient. It will work, but just not at the level of efficiency that may be needed at the time.  When demonstrating or practicing SWP, or VRS or whatever the term of the moment is, the minimum intent is to get the pilot to recognize the conditions that are conducive to VRS, AND recognize the initial indications of SWP.

SWP evolves into VRS. You should be taught that the vibrations from the main rotor system are your final warning before entering into VRS and should be thought of as a command from the aircraft to MOVE in any direction.

Recovery from SWP or VRS is the same, DIRECTIONAL flight.  The Vuichard technique is merely a variation of the method that's been taught for decades.  The use of tail rotor thrust to assist in lateral movement to exit the dirty air is not revolutionary, it has worked for quite a while.

I believe the reason we are seeing these accidents lately is that most pilots have never actually been in VRS and in practicing the escape method, they inadvertently enter actual VRS and panic. It can be horrifying to have a descent of ~600fpm accelerate to 4000+fpm in just a matter of a couple of seconds.  The aircraft literally "drops out from under you" and your instinctual reaction is to pull more collective which makes the aircraft descend even faster.  Then, the pilot who is now desperate to get away begins to input cyclic to fly away, but the rotor is operating in dirty air and the aircraft isn't doing what he told it to do. He panics even more and begins even larger cyclic inputs to get out of the situation.  Depending on the altitude the maneuver was started, he's either impacted the ground or chops his tailboom off.  Teetering rotor systems are most likely candidates for tailboom removal, but it can happen to fully articulated as well.

Rules:

-If you don't know what you're doing, you're not practicing, you're experimenting. Get some competent instruction.

-NEVER initiate SWP at less than 3000' agl.  5000' agl if you've done less than 20 iterations ever.

-If you find yourself in actual VRS, initiate DIRECTIONAL flight immediately, leave the collective alone and be patient.  It will take a few seconds for the handicapped main rotor to begin to get you out of that nasty air (the reason for the altitudes mentioned above).

-If you don't know what you are doing, get some competent instruction.

Practicing SWP/VRS is NOT a ground reference maneuver.  You must get zero airspeed within the airmass.  If you're using zero ground speed as your starting point, you're unlikely to get into even the beginning stages of SWP if you abide by the altitudes above.  If you're low enough for zero airspeed to equal zero ground speed, you're going to get hurt.

Remember, recognition, avoidance and timely escape are the goals.  And get some competent instruction. 

but you may need more altitude than you think for recovery 

I don't recall any VRS accidents that involved the acft hitting the ground with all the pieces still attached...just sayin'.

haven't been all that many before the Vuichard spree we're seeing.  VRS doesn't require that the tailboom gets chopped, just like LTE doesn't require it.

it appears that it is a problem with VRS training.