Black Square Bonanza

[waltpop 26]

Flying the Black Square Bonanza with the GTN750. Created a flight short flight plan from KHPN to KOXC.  Received MGS on 750, "VNAV Unable upcoming flight plan leg not supported."  Is that telling me one of my legs isn't in the database ? ? ? ? Thanks Walt

[ryanbatc 12,865]

I assume this is with the PMS 50 GTN - were you high enough up for it to calculate a TOD etc?

[waltpop 26]

TDI GTN 750xi. Not sure but I think that's what the problem might be. I look into that. Thank You Ryan

[ryanbatc 12,865]

6 hours ago, waltpop said:

TDI GTN 750xi. Not sure but I think that's what the problem might be. I look into that. Thank You Ryan

Hmmm - there's no full VNAV support with AP in the TDS.  But you can get VSR (vertical speed required) and the VNAV "banana" (the little blue arc) that shows up.  You need to first dial in an altitude and then start descending (or climbing) in VS mode.  The arc will change position based on how fast you are and what VS you selected.  Wherever it stops is when you will be at the selected altitude.

I've honestly never seen that message.

 

[Orlaam 311]

I'm fairly certain that if you pick an approach but don't activate it, the GTN will show that message.  It recognizes a descent path, but a discontinuity prevents the GTN from calculating the path.  So for example, you have an airport to airport direct flight plan active.  Then you hear on ATIS that a certain runway is active.  You select the ILS into that runway in the GTN but when it asks to Load and Activate, you just Load without activating it.  That is when I think the message pops up.  I used to see that a lot in the RXP GTN when I wasn't in a position to activate the legs yet.