Hello IPACS,
Sometimes the automatic MCP speed selection is not the same as the FMC speed, which could be the reason that VANV SPD was always on despite AT maintaining a (seemingly) correct speed.
I'm no expert in this but it seems like a bug 
Is it related to with the route planning & magenta line discrepancies you mentioned before?
The MCP is what ever the pilot sets. The FMC speed is what the flight management computer calculated.
If you use the copilot then the copilot will use the autopilot interface, i.e. the MCP (mode control panel) to adjust the speed.
Otherwise, if you are manually managing the aircraft without using the copilot then you as a pilot need to adjust the MCP speed when ever the numbers are displayed (window "open"). When the window opens it should set the last FMC speed if it happened automatically (e.g. when glide-slope is captured) or when you pressed a button like FLCH then the window opens with the current airspeed. Either way you need to manually adjust the airspeed from that point forward.
If VNAV is active then speed comes from the FMC and the MCP window is completely blank with no airspeed shown. The target airspeed is displayed on the PFD.
Thanks for the info, here's a screenshot of what i meant:
PFD shows 310 kts, FMC shows 330, MCP is blank
Thanks for the info, here's a screenshot of what i meant:
PFD shows 310 kts, FMC shows 330, MCP is blank
Now I see.
Yes the displayed values on the legs page come from the route. I have no access to the code of the route so these values remain incorrect for the time being, until the developer of the route fixes this.
