Hi allI have been trying to find the definition and differences between these 2 temps, could anyone enlighten me or point me to a site where they are discuseed.Thanks

Hi,as far as I know, i hope i am not wrong but then somebody will correct, TAT means the Total Aircraft Temperature (the temperature of the aircraftbody during flight) and TAS stands for the outside temperature. I am not really sure about the last one but some one will know better I hope!As example the TAT can be much more higher than the TAS at low altitudes and warm climate up to 10000ft or higher (don

Yes Matthias is right (although you may want to check the spelling of your abbreviations :) ). TAT is what's measured via the TAT probe and it's the outside air temperature plus the rise in temperature due to indicated airspeed and mach effect. The faster you go, the more friction with the air you have, thus the higher the temperature gets. The air data computer then calculates SAT by applying a correction to the TAT based on your IAS and Mach number.Iz

what about OAT?is there any difference between OAT and SAT?

I dare not call you by your nick :-)There should not be any difference, but some can be expected because, as pointed out, SAT is calculated from TAT, so sometimes a little error takes place.Usually, though, SAT will coincide with OAT. Before you ask yourself why is it that some planes then have SAT instead of just plain OAT (I just asked myself that question, and then answered it! Love when that happens!), simply it is because there is no way of measuring OAT in fast planes. The pure friction of the air against the probe causes the temperature read to be incorrect. That temperature is, as explained, the Total Air Temperature, which has to be corrected so we can arrive at SAT.TAT is of interest, for example, when considering what kind of temperature the skin of the wings (which in most cases is pretty much the outer skin of the fuel tanks, considering planes with "wet wings") is at, since fuel tends to not flow well at, say, -57

@ Iz :I am trying to get better each day with my english. Do not have many opportunities to speak that language! :-)Matthias

OAT = Outside Air TemperatureTAT = Termostatic Air TemperatureSAT = Saturated Air Temperature :-waveJose Rafael NavarroYV in I

...or in my part of the world...TAT = Total Air TemperatureSAT = Static Air TemperatureOAT = Something which goes into porridge :-hah