Temperatures (ISA, SAT, TAT)

[KirkR]

Have been studying the Challenger's cold weather related operations, air and fuel temperature and other criteria as the winter weather approaches.

ISA reference temp, static air temp (SAT) and total air temps (TAT) all are shown on the PFD(s).  Bulk fuel and engine fuel temperatures are shown on the MFD Summary page.

In what scenarios would the ISA reference temperature be used with the Challenger?  The other temperatures are clear in terms of operational reference/usage.

 

[FYG001]

Performance Kirk, such as in the FPCCM Manual, see following example (one of many)

[KirkR]

Ok, thanks.  ISA as a standard reference for the performance related information makes sense.  

 

[ozpilot]

Interestingly the Challenger has no OAT indication. A lot of pilots will use SAT instead since SAT is the temperature of undisturbed air around the airplane.  The AFM warns against this practice though since the SAT is only accurate when the aircraft is moving.  So if your on the ground you have to use the ATIS/AWOS or your iPhone!