Engine failure during a derated takeoff
Hi all,
I was trying to figure out at what point during a derated takeoff with an engine failure can we add power without loosing control.
This is how far I got before I got stuck:
Lets assume we had a V1 cut and we are airborne and climbing at V2.
That v2 was calculated for that specific derated power we are using.
At that point increasing power will increase Vmca, up to the point where VMCA would be greater than our current speed (V2) which means we would loose control of the bird.
According to that theory the first time we could increase speed is when we increase speed (i.e. @ Acceleration Height). But how much speed increase is "enough" for full thrust? and how much would be enough the next day while the A/C would have a completely different gross weight with different atmospheric conditions?
And this brings me back to my original question:
When does it become safe to add power on a derated takeoff with engine failure?
P.S.
Another problematic related scenario I just thought of is this:
What happens if the A/C is light and after takeoff we climb at V2+10 with all engines running, and at Thrust Reduction height we switched to CLB power (which in lighter gross weights is higher than the derated D-TO power), and after that increase in power we experience an engine failure? Didn't that increase in power just increased our Vmca but we still maintain the same climbing speed?
Any thoughts would be appreciated.
Thank u