bythenumbers
And I also assume as PIC you have taken into accountCAO 20.7.4 para 8.1
If not here is a little piece... "Multi-engined aeroplanes engaged in charter operations under the Instrument Flight Rules or aerial work operations under the Instrument Flight Rules must have the ability to climb with a critical engine inoperative at a gradient of 1% at all heights up to 5 000 feet in the standard atmosphere"
As no weight is specified it means at any weight the minimun is 1% and please take note of the word MUST. If it cant do it, its not legal. Enough said.
If you are implying it is illegal to fly a piston twin in charter under the IFR fully loaded in conditions that are hotter than the standard atmosphere then you are most definitely wrong. CAO 20.7.4 para 8.1 only states that the aircraft must be capable of achieving the quoted OEI performance at MTOW in the
“standard atmosphere”. There is no legal requirement for it to be able to achieve those OEI climb performance figures in conditions that are hotter than ISA and it most certainly doesn’t imply that it is illegal to fly one when it is hotter than ISA. As long as the aircraft can achieve the required normal performance figures in the POH then it is legal to fly, period. Any interpretation outside this is wrong.