Love the bun fight but I see nobody addressed the question.
The "except" part differentiates between thrust and idle where the intake pressure is very different. In the climb and cruise the intake temperature (T2) may well be equal or lower than SAT but during an idle descent the intake temperature could well be higher than SAT due to pressure effect. Thus the airframe may be operating below the magical -40°C but the intake temperature could be higher.
Last edited by FE Hoppy; 12th Aug 2012 at 19:33.