Issue with flightplan FBW 320N

[altenae 171]

Why is the flightplan (see below) in the MCDU only displaying it correct for 2 seconds in the Flightplanner screen.
After two seconds it's changed into the flightplan as you can see below.
It should go from DENUT to ATWIT as programmed in the MCDU.

Edited December 26, 2022 by altenae

[vonmar 123]

Hello altenae ,

I did a quick route , all ok (screenshot).

Would need more information on your data entry.

 

 

[altenae 171]

2 hours ago, vonmar said:

 

Hello altenae ,

I did a quick route , all ok (screenshot).

Would need more information on your data entry.

 

 

It was a flight from LEAL (runway 10) to EHRD (ILS-Y 24)
Why the sharp turn to EHRD and nog going via ATWIT

Edited December 26, 2022 by altenae

[Muds 31]

ATWIT is your final approach fix it's only like 10nm from Rwy24 threshold, but btw DENUT and ATWIT you are missing an entire STAR, so you are coming at almost 180° from your next leg and final landing course : DENUT -> ATWIT is 040ish then you turn left almost 180 degrees to ATWIT -> RWY24 on a 240 heading, that's why it can't be displayed correctly.

[Fiorentoni 4,227]

LNAV calculation doesn't yet include predicted speeds (which is actually VNAV calculations), so it thinks you're flying the turn with 300kts and therefore tries to draw a very early turn (because otherwise it would overshoot the turn completely).
It will be drawn correctly once you are at the actual speed down there, so nothing to worry about.

[holland786 504]

5 hours ago, Fiorentoni said:

LNAV calculation doesn't yet include predicted speeds (which is actually VNAV calculations), so it thinks you're flying the turn with 300kts and therefore tries to draw a very early turn (because otherwise it would overshoot the turn completely).
It will be drawn correctly once you are at the actual speed down there, so nothing to worry about.

Important to note that this is also not really an ideal path which you would keep IRL either.

 Airbus LNAV does not do anything magical with sharp turns, if it overshoots, it's not gonna try anything clever.

[holland786 504]

11 hours ago, altenae said:

Why is the flightplan (see below) in the MCDU only displaying it correct for 2 seconds in the Flightplanner screen.
After two seconds it's changed into the flightplan as you can see below.
It should go from DENUT to ATWIT as programmed in the MCDU.

Did you delete a discontinuiity ? This is not routing I'd expect in a valid flight plan.

[altenae 171]

6 hours ago, holland786 said:

Did you delete a discontinuiity ? This is not routing I'd expect in a valid flight plan.

No I did not. 

I have flown the flightplan and when I arrived at that point it was correct. 

Just like "fiorentoni" posted:

It will be drawn correctly once you are at the actual speed down there, so nothing to worry about.