Final answer:
When ENG ANTI ICE is ON, you will see indications on the PB such as changes in PT, TT, FF, and HPCD.
Step-by-step explanation:
When the ENG ANTI ICE is turned on, the Primary Boost (PB) shows certain indications. Firstly, the anti-ice pressure ratio controller will increase the inlet guide vane angle to provide more airflow to the engine. This increased airflow will cause the Total Pressure (PT) to rise and the Total Temperature (TT) to drop. Secondly, the fuel flow controller will increase the fuel flow to maintain the engine temperature by compensating for the cooling effect of the anti-ice system. This increased fuel flow will be indicated by an increase in the Fuel Flow (FF) reading on the PB. Lastly, the anti-ice pressure ratio controller will also increase the HP Compressor Bleed (HPCB) to remove the compressor bleed valve, which will lead to a decrease in the HP Compressor Discharge (HPCD) reading on the PB.