Agree with Robbiee.
First - RIP to the crew, professional investigation in time will tell what actually occurred - but we all wish it had never happened.
To add my bit to the conversation - I have been and still am instructing in the R22 since the early eighties - including original non tip weight blades - and have had no issues with rolling off the throttle for any simulated engine failure to the ground above 100 ft AGL on or outside the HV curve
using the following process:
Students have heard all the scary furfies so its about leading them into it slowly following me through bit by bit to keep their confidence.
I do not "chop" the throttle as I do in B47 or other higher energy systems.
Always Student briefed that there will be no surprise throttle chop for their entry - always proceeded with "on the count of three" etc.
Student required to lower the collective at a rate which "splits the needles" - ie- full down - not too fast/not too slow.
Student does not shut the throttle - reasoning is that - in the real thing - there is no need and that a habit learnt at this point against throttle governor and detent spring might slow the lowering of the collective as the wrist action of closing takes nearly a full second of valuable time.
I have the throttle and shut it fully as their collective goes down - always guarding the collective/throttle and pedals.
Hover OGE above 500 ft AGL (HV curve)- nose always pitches down/wait one second for flow to build/ RRPM stabilises around 94% before pointing nose to ground and then building rapidly as airspeed increases. Never an issue.
Student identifies collective full down and calls RRPM at full down no matter entry configuration. Then fly the machine without fixating on RRPM.
Cyclic and pedal input depending on flight condition - through transition/not through transition.(No Low RRPM horn/light system as deactivated at full down collective)
Student to understand from day one that its Main Rotor RPM which holds us up in the air and therefore about learning and implementing the process to initially maintain rotor speed (energy)as much as possible and then complete process to the ground (control inputs) dependant on where positioned in relation to HV curve and environment (wind/landing zone etc)
I always strongly guard the pedals to ensure that if the student inadvertently pushes the left pedal - yes it does happen - it is restricted by right foot on the right pedal.
I guess that the above is what most in this forum do anyway.. but have heard the occasional interesting story such as -
I know of one R22 many moons ago which went inverted and fortunately came back to upright about 100 ft AGL when an instructor was giving a student a hard time and unannounced throttle chops.
At 70 kts and about 900 ft AGL the student caught the instructor by surprise when he put in full left pedal at the same time that the collective went down faster than a speeding bullet.
Nose dropped rapidly/RRPM decay/rolled hard left/went inverted before restored to normal flight / lucky boys.
Engine oil went out the breather and down the tail boom.
Fly safe
