Uplinker:
jumpx3 is very kind with you to explain how it normally works, , and he is 100% correct .
I am however a bit puzzled by 2 points in your reply :
I have 16 years commercial passenger flying experience, including 10 years flying heavy twin jets (A330) longhaul
and
I did wonder if EVA015 had suffered a compass malfunction,
Not really compatible I would say.