Using 60 gallons of fuel, how long can the aircraft sustain flight at 55 percent power?

To determine how long the aircraft can sustain flight using 60 gallons of fuel at 55 percent power, it's essential to understand the relationship between fuel consumption, power setting, and the aircraft's endurance.

Typically, aircraft fuel consumption is expressed in terms of gallons per hour. For this specific scenario, if operating at 55 percent power, the aircraft is likely in an efficient power regime, leading to reduced fuel consumption compared to higher power settings. It’s common to estimate fuel burn at various power settings based on performance charts or pilot operating handbooks.

If we assume a specific fuel consumption for this situation, much of the aircraft's endurance will depend on how many gallons are used per hour at 55 percent power. When calculated, it generally results in a figure that suggests the aircraft can sustain flight approximately for 4 hours at this power setting based on the available fuel amount.

Therefore, if the total fuel available is 60 gallons and the consumption at 55 percent power equates to 15 gallons per hour, the resulting calculation would yield 4 hours of flight time. When going through the available choices, this makes the option of 4 hours the most accurate duration for sustained flight under the provided conditions.