How should trip fuel, contingency fuel, and final reserve be accounted for in planning?

• A. Sum the trip fuel and contingency fuel only.
• B. Sum trip fuel and final reserve, ignoring contingency.
• C. Sum trip fuel and contingency; final reserve is not included in total.
• D. Sum to determine total usable fuel; trip fuel for planned leg, contingency for unexpected events, final reserve as minimum required fuel.

Answer: (D)

In planning, you need enough fuel to cover the whole flight plus safety margins. Trip fuel is the amount required to fly the planned leg from departure to arrival at the destination, assuming things go as planned. Contingency fuel is added to cover uncertainties like headwinds, route changes, or longer actual burn than expected. Final reserve is the minimum fuel you must carry to handle delays or to reach an alternate if needed, ensuring you have a safety cushion.

So, you determine the total usable fuel by summing trip fuel, contingency fuel, and final reserve. This combination ensures you can complete the flight as planned, absorb unforeseen increases in fuel burn or delays, and meet the required safety minimum. The other options omit one of these essential elements, which could leave you under-fueled in real conditions.