@FFF: To the best of my knowledge nowhere is stated that these values are measured at or related to ISA conditions. In the Seneca, which has turbo's and thus constant pwr until app. 12.000' this is correct. There is a graphic in the manual in which you can see what happens whit VMCA after this alt. I don't know if there are comparable graphics in non-turbocharges aircraft, but I would like to know what they would say to ISA.
However, if you let your engine have more power at higher density, I will make my rudder more effective at higher density to counter for that!
Second, to the more flaps argument: The only reason I can see to fly with more flaps than recommended for t/o by the manufacturer (in normal flight operations i.e.) would be on the approach or during landing. Therefore, if we are to make a go around, the first thing in my crew concept is "g.a., set pwr for take off, set flaps... where you would fill in the normal number of flaps during t/o or at least a reduction of flaps. In other words, you would reduce your flapsetting ASAP to t/o cnfg. This would again lead to my worst case scenario, which of course relates to all "normal" flight conditions, whith all "normal" emergencies.
@zakka: In my original post I tried to give a correction on the, i.m.h.o., misuse of the VMCA definition by formulaben, and thereafter I tried to give an explanation to why VMCA would be higher with flaps lowered, as I thought this was an assumption that had to be cleared. This last part of my post was just my 2 cents worth, but as I re-read it, I can understand that you would have thought this to be my definition of the truth. I was reacting to one of the thoughts posted earlier in the thread, and missed severall of your comments in your post. Therefore to my statement that flaps would by definition raise VMCA, I stand corrected.
