ETOPS divert speed

[here_we_go_again]

Originally Posted by ElNull

thanks for the response. Isn’t the EDTO fuel calculation at the ETP (CP) based on the OEI-approved diversion speed? (the same speed used to define the EDTO area of operation)

In our Ops Manual, this speed is referred to as the “Company Speed” or “OEI Approved Speed”, and we even see it on the FMC > VNAV E.OUT > COSPD prompt. That makes me think it’s more than just a planning tool.

My point is: I’m not totally convinced this speed is only for planning.

My regulator very helpfully expanded on this. The bolding is my emphasis.

If minimum diversion time and getting the aeroplane on the ground as soon as possible are the most critical considerations, a high one-engine inoperative speed strategy may be selected, as permitted by the aeroplane’s fuel state, altitude capability and structural integrity. For two- engine aeroplanes, the time strategy is sometimes considered to be equivalent to the approved one engine inoperative speed, but a higher speed approaching VMO/MMO could be selected if conditions warrant. The flight crew is not bound by the speed assumptions used for EDTO flight preparation purposes.