[QUOTE]Apologies for the thread drift, but can anyone enlighten us on the effect low temperature has on the A320 FPV. Most folks believe that it is purely IRS derived, but it has a barometric input too which must be affected by temperature.
Of course the barometric input is affected. Depending on the ac, that is where the IRU gets the data from.
tried following the ILS GP in ISA -20 using the FPV and it appeared that around -3.7 was selected to maintain the GP but the actual FPV appeared to be indicating less than that. The sim was a CAE device recently upgraded to 1.9.
ILS is not affected by temperature. FPV ?? I thought even Boeing states not to rely on that...
Bottom line, the procedures are designed NOT to be corrected if within the posted temperature limits.