Under Discussion heading.
I’m going out on a limb here but I don’t like the way the second and third paragraph are written in that report under the ‘Discussion’ heading. I think they are slightly incorrect in their explanation. Surprising from an AAIB report. Or is it just me reading it wrong? Surely large blade ‘pitch’ angles prevent available engine power from increasing rotor rpm.? Not large blade coning angles?
The third paragraph :- yes reducing collective reduces pitch angle and then the rotor rpm can recover (not engine power recover. surely the available engine power is already trying to recover the Nr but is unable to) Once drag reduces due to decreased pitch angle, then the available engine power can return Nr to within normal operating parameters. Surely not “spin at full speed”?