December 26, 201510 yr Enroute from KIX to AMS with a fully loaded B77W KLM. I noticed during climb, my recommended flightlevel is much lower then my optimal flightlevel. Why is that?
December 26, 201510 yr Hello, Have a look at the FCOM v2 page 11.42.26 (pdf p. 1030). Opt, max and recmd altitudes are explained there. Romain Roux Avec l'avion, nous avons inventé la ligne droite. St Exupéry, Terre des hommes.
December 27, 201510 yr As far as I recall, "optimum FL" will take account of aircraft weight, INIT settings, etc, whereas "Recommended FL" will also take account of the length of the flight plan route. So although the optimum (from an efficiency perdpective) may be higher, if the leg is quite short, the recomended may be lower.EDIT: I've just seen that this was a leg from Japan to Europe, so the above is unlikely to explain it in this case :smile: Bill 😎FS2024 • Currently in 'GA mode' : A2A Comanche 2024 & Aerostar • Black Square C208, Bonanzas, Barons, TBM850, Dukes • COWS DA40 & DA42 • FSW Legacy, C24R Sierra & C414 • Echo Falco F8L • FFX HJET, Visionjet and P180 2024 • Got Friends A32 Vixxen • FSReborn Sirius TL3000, Sting S4 and Piper M500 • Flyboy Rans S6S • Skyward DA50RG • SWS Zenith CH701, RV-8, RV-10, RV-14, PC12 • Milviz C310R • Air Foil Labs Bristell B23 TrackIR • BeyondATC • PMS GTN Payware • RealTurb • Axis & Ohs • FS Realistic Pro9800X3D • RTX 3080 • 64GB DDR5-6000NPPL licence holder in the UK
December 27, 201510 yr As far as I recall, "optimum FL" will take account of aircraft weight, INIT settings, etc, whereas "Recommended FL" will also take account of the length of the flight plan route. So although the optimum (from an efficiency perdpective) may be higher, if the leg is quite short, the recomended may be lower. EDIT: I've just seen that this was a leg from Japan to Europe, so the above is unlikely to explain it in this case :smile: Not exactly. Refer to FCOM page I pointed on my previous post. Romain Roux Avec l'avion, nous avons inventé la ligne droite. St Exupéry, Terre des hommes.
December 27, 201510 yr Author I still don't get it. Normally the recommended flightlevel is much closer to the optimal flightlevel. Sometimes even between recommended and max. flightlevel. Why not in this case?
December 27, 201510 yr I still don't get it. Normally the recommended flightlevel is much closer to the optimal flightlevel. Sometimes even between recommended and max. flightlevel. Why not in this case? Have you entered some winds in the rte data? If yes, it may be because the FMC computes that for the next 500nm it is much more economical to fly at fl260, considering the actual weight and the wind while for the whole trip considering the actual weight and the CI, FL297 is more economical. If for the following next 500nm the winds went to be more favourable at a higher level, then the recmd FL would be higher. Romain Roux Avec l'avion, nous avons inventé la ligne droite. St Exupéry, Terre des hommes.
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