Fuel Policy and Fuel Monitoring — Page 32, Lesson 43

I want to walk you through the fuel monitoring phase of a flight. Once we've planned our expected fuel consumption on the ground, the job isn't done — we now have to make sure the aircraft is actually performing close to that plan, and we have to take appropriate action if it isn't. The commander of the aircraft is responsible for ensuring that fuel checks are carried out in flight at regular intervals. This isn't optional — it's a regulatory requirement. Each time you do a fuel check, you must record the fuel remaining and then evaluate it against three specific objectives. First, you compare the actual consumption so far with what was planned. Second, you check that the remaining fuel is still sufficient to complete the flight. And third, you determine the expected fuel remaining on arrival at the destination — that is, you project forward based on current burn rates. All of this relevant fuel data must be recorded. Now here's a critical decision point. If, as a result of an in-flight fuel check, the expected fuel remaining on arrival at the destination is less than the required alternate fuel plus final reserve fuel, the commander has a serious judgment to make. In that situation, you must take into account the traffic and the operational conditions prevailing at three places: the destination airfield itself, along the diversion route to an alternate aerodrome, and at the destination alternate aerodrome. Based on that assessment, you decide either to proceed to the destination aerodrome or to divert — but the overriding requirement is that you must land with not less than final reserve fuel. That's the absolute floor. Let me define those terms clearly. Alternate fuel is the fuel required to fly from the destination to an alternate aerodrome. Final reserve fuel is the minimum fuel required to fly for 30 minutes at holding speed at 1500 feet above the alternate aerodrome, or for 45 minutes for a turbojet aeroplane under EASA rules. So if your projected arrival fuel is less than the sum of those two, you're in a situation that demands immediate evaluation and possibly a diversion. Now, modern major carriers don't do this fuel planning by hand. They use computer flight planning. Some airlines install their own dedicated ground flight planning computer — for example, British Airways uses a system called CIRRUS, and Lufthansa uses LIDO. Other airlines subscribe to a commercially available system such as JETPLAN. The computer output usually comes on large sheets of fanfold paper, and I want to walk you through a typical print-out. In the example, line 18 is a list of the titles of each column, and the last entry in that header row is "REM". That stands for "Fuel Remaining". As you look down the columns, for each waypoint — names like KONAN, KOKSY, REMBA, and so on — there is a REM value. For instance, you might see 0045, 0043, 0038, and so forth. This is the minimum fuel that should remain overhead that waypoint, expressed in hundreds of kilogrammes. So 0045 means 4500 kg, 0043 means 4300 kg, 0038 means 3800 kg. All the pilot has to do is check, as he passes over each waypoint, that the fuel remaining is not less than the flight plan fuel shown in that REM column. If it matches or exceeds that value, he knows he has sufficient fuel to complete the trip and arrive with the appropriate reserves. It's a simple but powerful cross-check — one that keeps you ahead of the aircraft and out of trouble.