To allow anti-ice heat to engine sections, which switch must be ON?

• A. Engine A/I switch only
• B. Pitot Static Heat switch only
• C. Engine A/I or Pitot Static Heat switch on
• D. Both Engine A/I and Pitot Static Heat switches on

Answer: (C)

The system provides anti-ice heating to the engine sections through two independent feeds: Engine Anti-Ice and Pitot-Static Heat. Energizing either one completes the circuit that delivers heat to the engine anti-ice elements. That redundancy means you only need one path active to get anti-ice heat to the engines, which is why the correct answer is that either the Engine Anti-Ice switch or the Pitot-Static Heat switch being ON will allow anti-ice heat to reach the engine sections. If both are off, there’s no anti-ice heat reaching the engines. The other options are too restrictive because they imply only one path can supply the heat, whereas the system is designed to work from either source.