Which value is greater: Total Fuel or Total Usable Fuel?

Which value is greater: Total Fuel or Total Usable Fuel?

• A. Total Fuel
• B. Total Usable Fuel
• C. They are equal
• D. Cannot determine

Answer: (A)

The main idea is that the tanks hold more fuel than the engine can actually use. A portion of the fuel in the system is unusable—that is, it won’t be drawn up by the fuel pump under all conditions due to the fuel pickup design and the need to keep fuel from starving the engine during maneuvers or certain attitudes. Because of this, the total amount the tanks can contain (Total Fuel) is greater than the amount that can be used for flight (Total Usable Fuel). In the DA20-C1, you’ll typically see a small amount of unusable fuel, so Total Fuel is the larger value.

The main idea is that the tanks hold more fuel than the engine can actually use. A portion of the fuel in the system is unusable—that is, it won’t be drawn up by the fuel pump under all conditions due to the fuel pickup design and the need to keep fuel from starving the engine during maneuvers or certain attitudes. Because of this, the total amount the tanks can contain (Total Fuel) is greater than the amount that can be used for flight (Total Usable Fuel). In the DA20-C1, you’ll typically see a small amount of unusable fuel, so Total Fuel is the larger value.