TAT or SAT

[av8tor02]

I was just putting a book together and figured I would go with the best experience for this question. Anyone know what a great definition of TAT or SAT would be. Thanks in advance.

 

[ASH]

SAT is used on the ground

TAT is used in the air and is a derived temp.

 

[Smacktard]

I was just putting a book together and figured I would go with the best experience for this question. Anyone know what a great definition of TAT or SAT would be. Thanks in advance.

TAT = Total Air Temperature. This is the temperature of the air measured approximately by a temperature probe. It is higher than the static air temperature due to ram pressure, or Mach heating caused by the motion of the aircraft through the air.

SAT = Static Air Temperature. This is the temperature of the air surrounding the aircraft.

Indicated SAT and TAT shouldn't be used on the ground, or at least if you want accurate informtion.

 

[banned username 2]

SAT is used on the ground

TAT is used in the air and is a derived temp.

Actually TAT is a measured temp and SAT is a derived temp...

TAT is higher due to frictional heating.

SAT - Static Air Temperature and is the temp of still air.

 

[labbats]

*Sidenote*

I always thought that to determine the possibility of icing in precip, you used SAT rather than TAT. Is that correct?

 

[h25b]

yes go with SAT for determining icing conditions..

 

[AlbieF15]

Actually, SAT is what we do when drink beer with a bro...

...we SAT on the porch, boozed it up, and waxed about the old times..

TAT is 1/2 of what a nice looking bimbo has a great pair of.

I know these things as I am the consumate aviation professional (not..)

 

[FurloughedAgain]

I disagree with my good friend H25B.
On just about every aircraft that i've flown the manufacturer suggested that TAT be used in order to decide when to turn on the ice protection.

Why? Think of it in simple terms, TAT is the temperature that the skin of the airplane THINKS it is.

So if it is zero degrees C' and you accelerate to 290, ram-air, friction, etc. might yield a TAT of +11'C thereby eliminating the need for ice protection.

Now on those same aircraft SAT is used to determine when you may turn off the antiice when the temperature is so cold that any moisture it carries will be in the form of ice crystals (usually -40'C SAT or colder).

 

[dhampton]

What he said.... except at SWA we use plus 10 TAT

 

[Jeff Helgeson]

It's best to use SAT and TAT, don't forget RAT

What he said.... except at SWA we use plus 10 TAT

The DC9/MD80 uses RAT mostly.