View Full Version : Boeing optimum altitude and recommended altitude. Why does optimum not consider wind?

20th Sep 2023, 14:05
Why is it that the optimum altitude doesn’t consider the wind?

20th Sep 2023, 18:17
Optimum altitude is reasonably independent of weather conditions - and so can be readily determined using a fairly generic formula.
Including winds means you'll get a different answer every day - and includes data (winds at altitude) that is often not readily available.

20th Sep 2023, 18:38
In todays it is normal SOP to download a full windprofile for the whole route. If that is available, why wouldn't the FMCG not use it?

21st Sep 2023, 07:00
Recommended altitude wasn’t originally in our 757/67 FMCs

We had optimum and max, normally you wouldn’t want to go higher than 2000 above optimum so leaving that parameter in as a baseline is still useful

21st Sep 2023, 16:00
Which aircraft type?

AFAIK the term optimum altitude is used across many different Boeing types, but will indicate the same parameter. It was "created" for fleets starting from the 737-classic and still remains available on ie B777 (some have the ability to upload wind data inflight, some don't). There are always wind/altitude tradeoff tables that can be used to have more correct information.

Some Boeing FMCs provide "recommened" altitudes that take wind into account for a limited section in front of the route (I believe the 777 has this indicated), as wind data is considered only a forecast.