Practical flight-planning exercises: integrating wind, fuel, performance and mass data
Domain 10 is the integration exercise: one sector planned end to end from route, wind, performance, fuel and mass data with every limit checked.
The sequence
- Select route and level, applying the level table, route minimum altitude and wind.
- Extract wind and temperature per leg; compute WCA, ground speed and leg time, then total elapsed time.
- Take climb and descent time, fuel and distance from the performance tables; subtract them from sector distance to obtain cruise distance.
- Compute trip fuel from times and fuel flows; add taxi, contingency, alternate, final reserve and additional fuel for minimum block fuel.
- Check TOM ≤ MTOM, LM ≤ MLM, ZFM ≤ MZFM and the CG envelope; carry the final fuel into the load sheet.
- Populate the operational flight plan and the ATS flight plan consistently: total EET, endurance in field 19, alternates, levels.
Worked example
Route A–B 400 NM, track 090°T; B–C 350 NM, track 180°T. TAS 420 kt, wind 270/60 throughout. A–B: pure tailwind, GS = 480 kt, time = 400/480 = 50 min. B–C: crosswind, sin WCA = 60/420 = 0.143 so WCA = 8.2° from the right, heading 188°T, GS = 420 × cos 8.2° = 416 kt, time = 350/416 = 50 min. Total air time ≈ 100 min, trip fuel 4,120 kg. Fuel: taxi 200 + trip 4,120 + contingency 206 (5%) + alternate 350 + final reserve 1,225 (30 min at 2,450 kg/h) = 6,101 kg block. Mass: OEW 44,000 + payload 12,000 + fuel 6,101 = 62,101 kg ≤ MTOM 66,000 kg; ZFM 56,000 kg ≤ MZFM 57,000 kg. The plan is valid.
Traps
- Mixing decimal hours and minutes between legs, ending with a wrong EET.
- Using TAS instead of ground speed for leg times.
- Applying one fuel flow to climb, cruise and descent.
- Accepting a plan whose ZFM exceeds MZFM because the TOM check passed.
- Filing field 19 endurance below EET + 30 min.