I'm "wrong" all these years?
Hi Mr Axel,
pardon my ignorance but I do not understand some of your points.
U mention check distance between ETP to Suitable Div airports n make sure they are the same but isnt ETP based on TIME? that's why it's called Equitime Point.WHere the ETP will shift is dependent on winds factor & you apply the RWC/CWC formula.In my co.we are more concern if ETP is equal time rather than distance.
Also, in your example, it states 60min=450nm so 120min=900nm. but in both Boeing & AIB ETOPS manual & any performance person will know its not simply a case of rule distx2 as there is the diff of Driftdown slope from EventFL to FL100 (1LE).(depending on which strategy the airline will adopt).
Just wan to confirm.Thank U.
(ps,no offence but I do concur wz the rest here.)