Best Speed for a given Fuel Flow

[hevansrv7a]

Originally Posted by gmcjetpilot

Slower than most RV'ers are willing to fly. I'll take the philosophical approach and say there is one speed, it depends on your point of reference.

There is min speed which is not efficient*
There is max speed which is not efficient
There is best cruise, trade a little efficiency (range) for time*
There is best range, which is slow and gives max range
There is best endurance which is max time aloft or close to L/D max.
...

(emphasis added)

The speed for best endurance /time aloft is approximately 76% of the speed for L/D max and the Carson's speed is 1.316 times the L/D max speed. L/D max is approximately the best range speed, too, with corrections for wind. But that's what you meant, I know. Carson's speed in an RV is way below 75%. Even in my old C-150, 75% was beyond Carson's.

Of course, the original question wasn't about this but about how to best use the engine for a given speed. Or at least that's what I think he was asking. CAFE says Carson's speed is the optimum speed for efficiency.

[gmcjetpilot]

Originally Posted by hevansrv7a

(emphasis added)

The speed for best endurance /time aloft is approximately 76% of the speed for L/D max and the Carson's speed is 1.316 times the L/D max speed. L/D max is approximately the best range speed, too, with corrections for wind. But that's what you meant, I know. Carson's speed in an RV is way below 75%. Even in my old C-150, 75% was beyond Carson's.

Of course, the original question wasn't about this but about how to best use the engine for a given speed. Or at least that's what I think he was asking. CAFE says Carson's speed is the optimum speed for efficiency.

I was seeing if you where paying attention....ha ha Yep great points. Back to my real point in too many words, short, efficiency is an elusive thing and varies based on many factors, not the least is the human that wants to get there today. Some pilots define efficiency as getting there faster.

[cristian254]

Hey!, any of you guys knows what exactly is the Carson's Speed?, I need a clear concept. Thank you in advance.

[hevansrv7a]

Originally Posted by cristian254

Hey!, any of you guys knows what exactly is the Carson's Speed?, I need a clear concept. Thank you in advance.

Carson's Speed is your best L/D times 1.32, approximately.
http://www.eaa1000.av.org/technicl/p...s/perfspds.htm

[RV3 Pilot]

Originally Posted by hevansrv7a

Carson's Speed is your best L/D times 1.32, approximately.
http://www.eaa1000.av.org/technicl/p...s/perfspds.htm

Indicated or true?

[erich weaver]

Originally Posted by Mike S

Anyway, the method was WOT, keep on adding prop to min RPM, and lean, lean, lean.

This is consistent with what John Deakin preaches in his articles, although I was never able to discern exactly what "minimum RPM" meant. Kinda freaks me out when the engine gets quieter and quieter...

erich

[hevansrv7a]

Originally Posted by RV3 Pilot

Indicated or true?

Calibrated.
http://home.cogeco.ca/~n17hh/CarsonSpeed.html