ATA 30

Engine ITT Indicating
Scenario:
During a routine engine run/leak check following a scheduled inspection, the technician has started the number 2 engine first and keeps engine speed remaining at idle while the leak checks are performed. The right engine nacelle anti-ice valve has mechanically failed open, and HP bleed air is flowing to the right engine nacelle.
Answer:
There will be no cockpit indication except for higher Interstage Turbine Temperature (ITT); with one engine running, there is nothing to compare to. Since the switch is in the OFF position, no cockpit annunciators on the switch will be illuminated. To check for proper operation, the technician should turn the anti-ice ON after start and look for a rise in ITT and the ON and ENG light illuminated on the switch. Once verified, turn the switch OFF, and the lights should extinguish and ITT should return to normal.