Awblain
Sorry don't know what type of rotor your referring to, ancient metal weighted tip Blades maybe, composite blades bleed NR very fast, went from 100% to 90 % in about a second and that was waiting for it and knowing the throttle chop was coming.
It's exactly this misinformation that will cause havoc in the industry. A 214 and a 225 are completely different animals you can't generalize.
Reading thru this thread nobody seems to know what the starting parameters were of the helo in Glasgow? Ie what was the actual airspeed and altitude when the engine quit? Was it recoverable ? Nobody seems to know they are just speculating and offering advice on technique. it really doesn't matter why the engine quit. Likelihood of two engines quitting at the same time almost 0. That's what we should be discussing, before it starts most crashes involving multi engines occurred because they were operating in a performance area requiring two engines. Modern Helos have much better performance OEI and can be operated in a manner that does not require two engines.