LIRN IPKAM2Z LNAV trajectory

[DanielR]

This is IPKAM2Z for ILS S 24 into LIRN. I've manually modified altitude constrait at BENTO from 7500A to 7500, don't be surprised.

We're seeing that the lateral track RN411-BENTO seems to be completely off. The correct track is a right turn (DF leg) into BENTO after overflying RN411:

FMS navdata coding seems to be ok-ish (at least it's CF-DF conformal to AIP):

STAR:010,5,IPKA2Z,RW24,IPKAM,LI,E,A,E   , ,   ,IF, , , , , ,      ,    ,    ,    ,    , ,     ,     ,     , ,   ,    ,   ,LIRN,LI,P,A, , , , ;
STAR:020,5,IPKA2Z,RW24,RN411,LI,P,C,EY  , ,   ,CF, ,BAR,LI,D, ,      ,2669,0936,1290,0036, ,     ,     ,     , ,   ,    ,   , , , , , , , , ;
STAR:030,5,IPKA2Z,RW24,BENTO,LI,P,C,EE H, ,   ,DF, , , , , ,      ,    ,    ,    ,    , ,     ,     ,     , ,   ,    ,   , , , , , , , , ;

The 39.3NM trackmiles between RN411 and BENTO are far off. Interestingly, the vertical profile seems to be fine, with around 1850ft to lose between RN411 and BENTO on a 3° descent path. So the vertical profile seems to calculate a different lateral track internally?!

I can't say what the bird would have flown as I got a DCT BENTO.

Best regards,
Daniel

[Pils]

You were in cruise I assume? The map is drawn with your (likely enabled) half-bank mode taken into account. If you put a speed constraint in prior to the turn (say 200 kts) it might have tightened it up.

[DanielR]

Yes, I think this was in cruise. I'd argue that it shouldn't calculate with half-bank mode engaged when the trajectory is that low. Or does the real thing the same?

[ois650]

9 hours ago, DanielR said:

Or does the real thing the same?

Pro Line 21 calculates turns based off current speed (and also takes into account half-bank).

9 hours ago, DanielR said:

I'd argue that it shouldn't calculate with half-bank mode engaged

I agree, unfortunately the bones of Pro Line go back to the late nineties (released in 2000). I would say the guys with the knowledge to change this kinda stuff are long retired!