What is the purpose of the recirculation system?

What is the purpose of the recirculation system?

• A. It provides IDG cooling through fuel flow
• B. It purges air from the fuel lines
• C. It heats the fuel
• D. It increases fuel capacity

Answer: (A)

The recirculation system is there to keep the Integrated Drive Generator (IDG) cool by circulating fuel through its cooling path. A portion of fuel is continuously looped from the engine feed, through the fuel/oil heat exchanger that cools the IDG, and back to the tanks. This is especially important during start and low engine power when fuel flow to the engine is limited; without this recirculation, the IDG could overheat. Heating the fuel, purging air, or increasing fuel capacity aren’t the purposes of this loop, so the cooling through fuel flow is the correct function.

The recirculation system is there to keep the Integrated Drive Generator (IDG) cool by circulating fuel through its cooling path. A portion of fuel is continuously looped from the engine feed, through the fuel/oil heat exchanger that cools the IDG, and back to the tanks. This is especially important during start and low engine power when fuel flow to the engine is limited; without this recirculation, the IDG could overheat. Heating the fuel, purging air, or increasing fuel capacity aren’t the purposes of this loop, so the cooling through fuel flow is the correct function.