Can’t comment on the bus but on the boeing you can’t deduce the state of the modes by looking at the MCP!
You can see what is deselectable, that does’t give you the complete picture.
e.g.
in alt hold, the mcp button might NOT be illuminated.
an illuminated VORLOC button could be armed not engaged.
an Illuminated AP button isn’t necessarily engaged (e.g early part of intended 2 channel approach)
This is why you look at the FMA not the MCP
how the **** do people not understand this? Why is the question even being asked?
**** training, that’s why.
this industry need to stoo cutting corners and pull its head out of its arse.
FFS. Somebody shoot me.