Under standard ICAO flight planning regulations, contingency fuel is commonly calculated as 5% of the planned trip fuel. If the planned trip fuel for a flight is 800 kg, what is the required contingency fuel?

### Why this is right Five percent is 0.05. Multiplying 800 fuel units by 0.05 gives 40 fuel units. ### The concept The contingency is calculated as a percentage of trip fuel, not as 5 percent of the final total. Convert the percentage to a decimal, multiply by the stated base, and retain the same fuel unit. ### The other options - **4 units**: This results from using 0.5 percent instead of 5 percent. - **80 units**: This is 10 percent of the trip amount. - **400 units**: This is 50 percent of the trip amount. ### Worked numbers - **Given**: trip fuel 800 units; rate 5 percent. - **Find**: contingency fuel in the same fuel units. - **Formula**: contingency = rate × trip fuel. - **Solve**: 5 percent = 0.05; 0.05 × 800 units = 40 units. - **Answer**: 40 units. - **Check**: 40 is 5 parts per 100 of 800. ### Terms - **Contingency fuel**: The additional fuel set at 5 percent of trip fuel. - **Fuel unit**: The common unit used to quantify the fuel amounts in this calculation. ### Remember Five percent means multiply by 0.05.