Panama Jack wrote:
-- the performance penalty is something like 2%.
Actually, it more like 0.2%. Tried it during cruise (FL240, ISA-5) the other day and saw .3% drop in torque.
Also, there is an AFM limitation at ISA+25: with SAT above this temperature the doors need to be closed. Presumably this is to force more air through the oil cooler instead of letting it out the bypass door.
PD.