Jov

Optimal flight level changes to lower FL during flight

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Flight LSGG - EKCH.

Fuel is planned with fuelplanner according to flightplan,

Opt FL at beginning of the flight is 370. After some time that changes to 375.

ca. 280 mi b4 reaching the destination instead of changing to 380 (what I expected)

OPT changes to 352 and then to 332.

Tailwind is 40 kt, no unusual weather.

 

Is that a normal behavior?

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2 hours ago, Jov said:

Flight LSGG - EKCH.

Fuel is planned with fuelplanner according to flightplan,

Opt FL at beginning of the flight is 370. After some time that changes to 375.

ca. 280 mi b4 reaching the destination instead of changing to 380 (what I expected)

OPT changes to 352 and then to 332.

Tailwind is 40 kt, no unusual weather.

 

Is that a normal behavior?

 

Did you create and then load a flight plan, or did you enter it manually?  If you created one, which software did you use?

 

 

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The flightplan comes from FSC, not entered manually.

The OPT drops further during the flight. @ TOD it was something
like 253.

It seems odd, since OPT should rise instead of fall with fuel burn.

 

It does btw with long haul planes (PMDG). I always create the flightplans

the same way.

 

Why do you think that the flightplan coult affect the OPT level?

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I had misread your post, and was wondering if a step climb (small phone) and had worked itself in.

 

We are currently testing a new updated FMGS, lets see if that resolves this for you.

 

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Did more testing, results are consistent.

 

A319 EKCH-LSGG; Flightplan FSC, imported from file (without SID/STAR).

Same result. first OTP rises and then begins to decline towards the TOD,
Funny: I had to change the RW for landing and the approach, so the flight turned out
to be longer. The OPT FL rose again to then decline towards the TOD.

 

Next flight A320 LEMD-LSGG.

Flightplan entered manually. Same result

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