Good morning all!
It has been my understanding that A/P (or FCCs) L, C and R uses IRU L, C and R respectively. Also, the CPT and FO IRS source selectors are irrelevant in regards to the autopilots, in contrast to eg. ADC source selectors.
In my last sim the IRU R failed while flying on A/P R. The NNC finally ended with us putting IRS R to OFF, but there were no mention of any deferred items. We flew on A/P R for the remainder of the sim. Only LAND 2 was available for landing.
I'm no system expert but I would imagine that a attitude source was required for the autopilot to stay engaged.
Do anyone have insight in how this work?
Best regards,
Bluescan