SS - Your response concerns me - you say I got my facts wrong. You say the red low fuel light comes on at 48kg remaining. The manufacturer says 60kg, according to Airbus Helicopters' information as posted earlier. They also say then you must land in 8-10 minutes. Given that, I would take the lesser time of 8 minutes as the limit, but I'm surprised you want to take the longer end of the at 10 minutes. Maybe I have misunderstood something, but perhaps you could review these "facts" and set out what they really are?
Anyway, it seems that you have agreed that you would not actually land when you had just 70kg in my example, which was the original point.
Thanks for all your EC135 fuel indications info btw, it has been very helpful!