Commercial Pilot Airplane (CAX) Performance Practice Exam 2026 – The All-in-One Resource to Master Your Aviation Success!

To determine the average groundspeed of an aircraft based on its fuel consumption, it's essential to understand the relationship between fuel flow, distance traveled, and groundspeed. In aviation, the average fuel consumption is often measured in gallons per hour (GPH), while groundspeed is expressed in knots.

The average groundspeed can be approximated if you know the aircraft's range and its fuel consumption rate. If, for example, an aircraft consumes 15 gallons of fuel per hour and has a specific consumption efficiency that correlates to its groundspeed, we can derive a reasonable estimate of its performance.

In this scenario, the correct answer of 160 knots likely corresponds to a common performance parameter in many general aviation aircraft where a fuel flow of 15 GPH relates to a cruising speed in the range of 160 knots. This groundspeed would be typical for many single-engine or light twin-engine aircraft that operate efficiently at that consumption rate.

The other options (120, 150, and 180 knots) do not match this typical performance metric as closely, and either fall short of or exceed the expected performance for an aircraft at 15 GPH. Therefore, the average groundspeed of 160 knots aligns well with expected aircraft performance for a fuel consumption