Contingency Fuel — Fuel carried to account for unforeseen deviations from planned fuel consumption.

Contingency Fuel is the amount of fuel carried to compensate for unforeseen factors that could increase fuel consumption beyond the planned trip fuel — such as weather deviations, ATC routing changes, stronger headwinds, or holding at the destination. It is a mandatory component of fuel planning.

• Typically calculated as 5% of trip fuel (or 5 minutes of holding fuel, whichever is greater)
• Statistical methods or 3% may be used by operators with approved fuel monitoring programs
• Cannot be used to compensate for known factors — those require extra fuel
• Part of the minimum fuel calculation per ICAO Annex 6