Trip fuel must be realistic — Page 23, Lesson 36

I want to walk you through the concept of Trip Fuel — this is the fuel you plan to burn from engine start at the departure airport all the way to landing at the destination airport, but it's not just a simple number. Let's start with the core principle. Trip fuel must be realistic. There's no point in coming up with an unrealistically low figure just to save money or reduce weight. It has to be based on what you actually expect to happen during that specific flight. So, you take into account the most likely routing — not a straight line from departure to destination, but the actual route you'll fly. For example, if the departure airport requires Standard Instrument Departures (SIDs) — those are published departure procedures that keep you on specific tracks for noise abatement, terrain clearance, or air traffic control separation — or if the destination airport requires Standard Instrument Arrivals (STARs) — the published arrival procedures — then those SIDs and STARs can add tens of miles of track distance to the en route portion of the trip. You must include those extra miles when calculating your trip fuel. Now, the regulations are very specific about what the planning must be based on. The operator — that's the airline or company you fly for — shall ensure that flight planning is based only on: - Procedures and data derived from the Operations Manual or current aeroplane-specific data. So you're not guessing; you're using the approved numbers from the manual for that specific aircraft. - The conditions under which the flight is to be conducted, which includes: - Realistic fuel flows expressed in kg/h, lb/h, or gal/h — kilograms per hour, pounds per hour, or gallons per hour. These are the actual consumption rates you expect. - The aircraft's anticipated weights (masses) — how heavy the aircraft will be at each stage of the flight. - Expected meteorological conditions — the weather you're forecasting, like winds aloft, temperature, and pressure. - Air Traffic Service procedures and restrictions — any ATC-imposed routings, altitude constraints, or holding patterns. Now, let's look at the Fuel Policy Diagram that's part of this excerpt. It shows how trip fuel fits into the overall fuel planning structure. I'll walk you through the components from the diagram. Starting at the Departure Airfield, you have your Trip Fuel — that's the fuel to get you from departure to destination. But then you add Contingency Fuel. Contingency is calculated as 5% of Trip Fuel or 5 minutes of destination fuel flow at 1500 ft, whichever is the greater. And importantly, contingency can be assumed to be unused — it's there as a buffer for unforeseen circumstances like routing changes or wind variations, but you plan to not need it. Then you have Alternate Fuel — that's the fuel to get from the destination to an alternate airfield if you can't land at the destination. After that comes Final Reserve Fuel — a mandatory minimum amount of fuel that must remain in the tanks upon landing at the alternate or destination. And finally, Taxi Fuel — but note the important caveat: Taxi fuel is NOT included in Total Endurance calculations. Total endurance is the total time you can stay airborne, and taxi fuel is burned on the ground before takeoff, so it doesn't count toward your airborne endurance. All these components add up to Total Block Fuel or Ramp Fuel — that's the total fuel you load onto the aircraft before pushback. So, to summarise: Trip Fuel is the realistic, route-specific fuel for the planned flight from departure to destination, including SIDs and STARs, based on approved data, realistic fuel flows, weights, weather, and ATC procedures. It's the foundation of your fuel planning, and everything else — contingency, alternate, final reserve — builds on top of it.