The thread title gives a clue. It's supervision of an endorsed pilot, NOT training. The rotary world suffers from this more than most, since Transport Class A R/W is >2750kg, and our endorsement criteria is based on Transport class (A or B). Hence, a 'simple' helicopter of only 3200kg, because it is classed as Transport Class A, requires 10 hours endorsement training (with, of course, a QHI) then 15 hours ICUS before VFR charter is allowed by the endorsed pilot, and 25 hours before IFR charter. The complexity of the helicopter is irrelevant, the weight is the only criteria. There are helicopters of <2750kg which have far greater systems and handling complexities than many mid 3 tonne machines, yet they have only 5 hour endorsement requirement
Now, why on earth would we want to do the ICUS time with an instructor? Maybe if it was the pilot's first multi and he/she was a bit shaky through endorsement training we would, but otherwise, it's generally a PITA that is hard to justify. I've even flogged ML -SY - ML just to run off the hours, that's a lot of non rev to justify, without the added inconvenience of cranking up the criteria of the supervisory pilot! Until CASA reviews its criteria (and the sun rises in the west
) we are stuck with a requirement that makes no allowance for the experience of the pilot being endorsed and supervised (at least, in the rotary world). I see no reason to make it more restrictive.