Originally Posted by Potsie Weber
For us, planned speed is simply that - planned speed to establish the area of operation. There is no need to actually fly at that speed if you had a decompression.
Of course not. In case I didn't state it clearly enough, the planned speed I was referring to is the speed at which the flight planned time and range assumptions at the ETP
for the contingency being considered are based. The actual situation at the time of occurrence may give cause to select a different speed. But since the fuel burn estimates used in the flight plan contingencies were calculated using a specific speed, it's a good place to start until the
actual situation can be assessed and the plan adjusted accordingly.
Summarizing oceanic planning considerations into a format suitable for the purposes of a discussion like this is challenging to say the least. A comprehensive computer based flight plan package contains far too much information to whittle down to a few paragraphs. And there are more things to consider than can be accounted for in a few words. The automation of flight planning provides fast accurate data, but also makes understanding the assumptions and decision matrix more challenging. It all seems a bit more sensible when marked up on a plotting chart.
westhawk