It is more accurate to say that the RMI displayed true air
temperature (TAT) has been corrected for compressibility based on
Indicated Air Speed as measured thru the pitot tube. At 200 KIAS, the
OAT is reported as measured at the probe location and is usually higher
than the TAT.
Scott Krueger
AKA Grayhawk
Lancair N92EX IO320 SB 89/96
Aurora, IL
(KARR)