##
4-4 Thrust Rating Computer

1.
The TAT window displays the total air temperature.
2.
The THR LIMIT window displays the N1 limit for the selected limit mode. The N1 limit is calculated out of TAT and the plane's current altitude. No indication is displayed when no thrust limit mode is selected.
3.
The LIM MODE window indicates the thrust limit mode. No indication is displayed when no thrust limit mode is selected.
4.
The thrust limit mode is selected by these four buttons. There is one button for each mode.
5.
The TARGET window displays the computed target N1 limit when the FLXTO button is selected ON. When the button is off, no indication is displayed.
6.
The TEMP window displays the selected FLEX TEMP. FLEX TEMP can be set by the knob below the window. The window is empty when the FLXTO button is selected OFF.
7.
The AUTO mode accellerates the engines to the set limit or the FLEX target. The AUTO mode automatically turns off when the Autothrottle is switched on.
8.
The FLXTO button activates the FLEX TO mode and disactivates all other TRC limit modes.