Helicopter rotor brake question
I hope that this is the correct forum for this question, which arises after watching the BBC ten o'clock news last night about the sad accident to the Super Puma. I have no experience in helicopters, but being in engineering/design and R & D for many years I have a keen interest in all things mechanical and I believe that test pilots are most likely to share my feelings for the machine and manufacturer's intentions as opposed to day to day operations.
There was a film-clip in this news item showing a Super Puma from the same fleet as the lost aircraft, taxying in and shutting down. My attention was drawn to the apparent speed at which the rotor stopped, I am used to seeing helicopter rotors slow quite sedately and finally creep to a halt, but this was noticably quicker, I realise that the clip could have been edited, but my impression of a quick stop was reinforced by the fact that immediately after rotation stopped, the whole head "kicked back" a few degrees as if the remaining momentum in the blades had wound-up the head/gearbox mountings, and this was released as the flexed blades rebounded in the disk-plane.
I was under the impression that rotor brakes were fitted to prevent windmilling when parked and not to save a little time in the shutting down process. As an engineer, this treatment seemed to me to be a rather harsh way to treat a highly stressed mechanism. Is this correct, or am I being over sensitive? I realise that these reversal loads are probably miniscule compared to the centrifugal loads the blades put on their fixings but it all just seemed rather brutal, like selecting "Park" on an auto gearbox before actually stopping!
Thanks for any opinions.