Why is measuring fuel quantity in pounds more accurate than in gallons?

Measuring fuel quantity in pounds is more accurate than in gallons primarily because fuel volume can change significantly with temperature fluctuations. As the temperature increases, the fuel expands, causing its volume to increase. Conversely, when the temperature drops, the fuel contracts and the volume decreases. Since aircraft operations require precise fuel measurements for safety and efficiency, weighing the fuel in pounds provides a consistent and reliable measurement that does not fluctuate with temperature. This allows for a more accurate assessment of the fuel on board, ensuring that calculations for flight planning, weight and balance, and performance are based on actual weight rather than potentially variable volume.

Other choices do not address the fundamental issue of variability due to temperature. While fuel weight does vary with different types and densities of fuel, it is inherently more stable compared to the volume measurement affected by temperature changes. Additionally, the convenience of measurement in pounds or other standards does not impact the inherent accuracy of the measurement itself in varying conditions.