GenX engine uses T12 instead.
1. The T12 sensor supplies the fan inlet air temperature data to the electronic engine control (EEC).
2. The EEC uses the T12 sensor as backup to the airplane total air temperature (TAT).
- TAT is used for control function and power management of the engine.
- If TAT is not available from the airplane air data reference system, the EEC uses T12 data.
3. The EEC compares the compensated T12 value to the TAT provided by the airplane.
- If the airplane TAT and compensated T12 temperature agree within +/- 2.5C, the EEC uses the airplane TAT for its final selected TAT signal.
- This is the signal used for thrust management.
4. The EEC uses T12 to calculate:
- Mach
- Altitude
- Calibrated air speed (CAS)
- Standard day temperature.
5. The EEC also uses T12 for:
- Thrust scheduling
- Variable bleed valve (VBV) control
- Variable stator vane (VSV) control.