Unrealistic planning of Flight Levels during a portion of the flight

With respect to flight HECA-EHAM, MPH8342 - PH-CKB, planned 02FEB2024-09.10UTC:

On the first OFP page, under FL STEPS: HECA/0360/MOOCE/0240/MASEK/0380 a descent is planned from a comfortable F360 to FL240 at WPT MOOCE (TTLT 0327), then a climb is planned to FL380 at WPT MASEK (TTLT 0343).

Looking at data in a downloadable XML file for this flight, FIR valid levels at WPTs MOOCE & EKSOS are shown as 6000, 8000, …, 22000, 24000. FIR valid levels from MASEK onwards are 26000, 28000, …, 59000, 63000. For WPTs in between EKSOS and MASEK valid levels are shown as 6000, 8000, …, 59000, 63000.

In the German Aeronautics Information Publication (AIP, valid date 25JAN2024, ENR3.2-L-6) for airway L604, restrictions are shown for eastbound flights only between WPTs ANELA and MOOCE (available at FL245 and below). This planned fight was westbound, for which no such restrictions were applicable. I think, the flight could have been planned continuously at F360 (or FL380).

One other remark on this XML file…: where it says “ind_airspeed”, I would say that this number equals Equivalent Airspeed [EAS]; the speed shown on the Primary Flight Display [PFD] would be slightly higher. For instance near WPT RODIS: IAS is calculated as 261 kts in the XML file, the PFD - however - will show 278 kts (Calibrated Airspeed [CAS] for the atmospheric conditions at this WPT). IAS does not show on the LIDO flight log pages, it does however on the DAL format. And I think they are the incorrect lower EAS values.

Kind regards,

Hi Simon, thanks for the reports.

For the first issue, this is due to a coding limitation of the AIRAC data from our data provider. Airways with a one-directional cap sometimes cap both directions at that level.

I have added a manual override to fix this case in SimBrief at least.

For the IAS vs EAS issue, I think this should also be fixed now.

Best regards,


Thank you for looking into the AIRAC issue.

IAS values are much closer now to the values that I calculate, but still showing between 2-5 kts lower. I am using two different formulas* that both return the same CAS value. But this is great already.

Thank you for looking into this.

Kind regards,

  • 1 - Eurocontrol’s BADA User Manual 3.8 (available on the internet), formula 3.1-24
    2 - “Introduction to Flight” by John D. Anderson, JR; fifth edition, formula 4.78 (ISBN 007-123818-2)

Hi Simon, I have made further adjustments. Let me know if it matches better now.

Best regards,

Hi Derek,

Great job: there now is an exact match!

Thank you again, and with kind regards

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