According to the performance data, the range at 55% power, 6000 ft, 7.9 GPH, and 104 KTAS is approximately how many nautical miles?

• A. 500 nm
• B. 600 nm
• C. 700 nm
• D. 631 nm

Answer: (D)

Estimating range from performance data comes down to how far you can fly on the fuel you have. Endurance is the time you can stay airborne at the given power setting, calculated from usable fuel on board divided by the fuel flow (GPH). Here, the burn rate is 7.9 gallons per hour at 55% power, and the data gives you a specific amount of usable fuel. Endurance = usable fuel ÷ 7.9.

If usable fuel is about 48 gallons, then endurance ≈ 48 ÷ 7.9 ≈ 6.1 hours. With a true airspeed of 104 knots, the range is 104 × 6.1 ≈ 634 nautical miles. This rounds to approximately 631 nm, which matches the given choice.