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Fuel Requirements

Typically there is a legal minimum fuel limit that all pilots must follow when planning a flight. The minimum amount of fuel will be enough to supply all of the following:

• the ability to fly the aircraft from its departure airport to its destination airport
  
• the ability to carry out an approach and go-around
  
• the ability to fly to a nearby alternate airport
  
• the ability to fly a 30-minute, holding pattern above the alternate airport
  
• the ability to land and taxi to the gate

To calculate the amount of fuel needed for a flight, the pilot uses the following equation:

Fuel Flow (gallons per hour) x Time = Fuel Consumed

The pilot uses charts found in the aircraft operation handbook that provides information about the miles per gallon of the aircraft at certain weights. The weight of the fuel is calculated by taking the total number of gallons and multiplying it by 6 pounds. One gallon of fuel weighs 6 pounds. This is usually figured into the charts found in the handbook.

Once the pilot knows the aircraft's fuel consumption rate for the weight being flown and the flight time, the pilot can compute the fuel needed for the flight.

Look at the example below.

First convert the flight time from hours and minutes to decimal hours:

1 hr 40 min = 1 hr + 40 min/60 min = 1.67 hrs

Now you can use the above equation:

8.5 gph (fuel consumption rate) x 1.67 (flight time in decimal hours) = 14.2 gallons

The pilot of this aircraft will need to make sure that at least 14.2 gallons of fuel are pumped into the fuel tanks for this flight.