So the only way to cross check its operation is via the standby instruments... what is the difference then when you hand fly. how can you cross check the instruments then.. I suspect it's also via the standby instruments. so u see it makes no difference if you fly or the A/P flys. The cross check issue is still the same.
What i said was that the Autopilot itself can't cross check it's progress because it only has 1 set of input data.