Tom,
Just a quick q - on your chosen aircraft where you
may retract the flaps at V2+10 - what is your en-route (ie clean) climb speed? What is your manouvering speed clean?
I am not saying that no aircraft exist where you don't climb clean at V2+10, but for most of the serious kit out there, V2+10 (or whatever is specified) is a transient speed, not a speed you continue flying.
On my current aircraft the gap between flap retraction (V2+12) to Vfto is in the order of 20 kts, and on the 737 it was around 25 kts.
If you can explain how you get from V2+10 to Venr without busting your gradient OEI (or indeed, explain how climbing below your Venr clean improves the gradient OEI), I shall be most impressed - or a grand richer
