I'm jumping into this discussion from another Erebus thread. In it, I was hoping to get feedback from pilots on two very basic questions that seem to get lost in the shuffle of technical points thrown back and forth. As an amateur aviation safety enthusiast, I'm wondering if there is general pilot consensus here:
1) that reliance on AINS (at the time) is/was not considered a fail safe alternative to ground-based instrument guidance, and therefore is not permitted as a substitue when in IMC?
2) A visual descent not only requires being VMC, but requires firmly establishing your position visually BEFORE dropping below MSA? (If this is so, how can anyone find the crew of 901 100% blameless?)
After reading countless debates on many forums on F901 I still am not sure I have the definitve answers to these questions.
Thanks