Baron, thanks for the reply
ref your quote
"Greater groundspeed equals longer take off run, and a greater distance to
achieve the same altitude, which means a reduced angle of climb "
I’ve meant climb only, no wind, at V min drag, so I’ve not included take off, or ground. Seems we
disagree on the climb angle. My understanding was that it is independent of temperature, for
constant thrust ie flat rated engine. Does anyone have a Boeing or Airbus Final segment chart
to verify this. As I said previously, the Dassault Falcon 50 chart shows this, but it could be wrong.
Your quote
"For the same CAS drag must be the same, so thrust required must be the same, excess thrust the same, so rate of climb the same
I agree with you first two phrases, the third should mean climb gradient the same, no? After
all, it’s excess horsepower that determines climb rate, and excess thrust that determines the climb
gradient. And bookworm seems to agree climb gradient is the same
I still keep getting that the aircraft climbs at a better rate, at min drag with flat rated engines
??
Bookworm, good to hear from you. You must be referrring to barons quote above
My understanding is that flat rated means just that. As temperature would rise, the engine will
speed up in order to maintain the thrust. Until the predetermined temperature, usually ISA plus
something, say isa plus 15, equals 30 deg C. This is at sea level, adjusts for Pressure altitude. I
believe most modern turbofans are somewhat flat rated to isa + 15 deg or more.
I’ve been attempting to show that a flat rated aircraft at min drag speed will climb at a better
rate when the temperature is warm, versus cold. If you say the gradient is the same, which I
thought, then it seems the next logical step is that the rate of climb is higher when warm.
And so, it is just an illusion that the colder it is, the better the rate and gradient. Paradox solved