BJJ, I think the discussion itself is a good one and I´m not too sure that Toms theory is complete bollocks....
The discussion has changed and in the beginning we were talking about all engine performance and noise footprint...now we are at OEI performance...
By the way, IIRC is the difference net to gross gradient 0,8 on the 2nd (2 engines) and 1,1 on the enroute climb (too lazy to look it up right know), so the difference is almost neglicable and if we bear in mind that the enroute climb is in MCT and the 2nd is T/O thrust then his theory has its merits. (I havenßt got the numbers to crunch it or prove it)
Also Cessna has elected to stick to one Venr for all weights. I would guess that this speed would normally also change with weight. Most likely Cessna has found the difference to be so small that for the benefit of the average stupid flying the C680 (such guys like me) it sticks with just one speed....
Manufacturers like to save money time and hassle and tend to make just the necessary documentation and I think the legal implications especially in the US might be a contributing factor.
The real question for me stays the same: what do I do when one donk goes awol after the flaps are retracted, I´m somewhere between V2+10 and Venr and there is an obstacle I still have to make. (what gradient am I doing) Our CL / AFM doesn´t give guidance here and I admit it, I haven´t thought about this scenario before and certainly have not trained it with FSI.
I think it is a valid question, OTOH its not a scenario that happens often and to the best of my knowledge there has not been one accident where this had played a role...
Its not practical to stay at V2+10 with both engines and flaps til clear (I´d block the departures at 120-130 KIAS...)
Last edited by His dudeness; 4th Dec 2012 at 08:54.