This distance, if published, is normally base on a descent at a certain speed, normally max or high speed,
Are you sure about this? Look at an ETOPS manual, take the TAS @ 10,000 ft and multiply it by your approval time, i.e. B772 375 TAS x 2 hours = 750 nms..... but the area of operation is 840 nms, how come?
For OEI in ETOPS = go fast.
Why?
Whenrealityisapain.... what would you do if you couldn't descend to a low enough altitude for normal breathing, would you increase the amount of oxygen on-board, and if so, how?
Mutt