I'm helping my friend on his "homework" and the homework is about EC120, more exactly climb performance. The task requires to take-off with external cargo TOM = 1300kg at 1.000m, 8ºC and climb to 2.500m, -1ºC (ISA temperature gradient) to unload the cargo.
From the start, I really don't understand the origin of "corrected mass" but I must be getting the charts wrong as I get more climb performance at 2.500m than at 1.000m.
Corrected weight (5.8)
Rate of climb (5.9)
any ideas where I got it wrong?