VNAV switch to kts approaching TOC

[captain_alligator]

Two flights in a row, I have found VNAV trying to maintain airspeed in KTS near the top of climb, which it can't do - the set speed is higher than the barber pole and it ends up stuck one or two thousand feet below cruise altitude, trying and failing to gain speed. I actually only noticed it because I'd stopped climbing. On the second occasion, it definately had switched to Mach (0.73 I think) during the climb, then at some point close to TOC it had reverted back to KTS.

To fix the problem during flight, I selected LVL CHG, switch to Mach, dialled it down to something sensible, then re-engaged VNAV.

Screenshots and log files attached.

 

GizmoLog.txt

Log.txt

[Litjan]

Huh, that is strange - we are forcing the switchover once past a certain altitude - so I wonder what happend. Thanks for the report, we will try to recreate (and fix) this!

Cheers, Jan

 

[Veace]

I personally haven't ever got this kind of problem in any hotfix that was released