Question about Mixture Control

[John Ceglarek]

Can someone please explain how mixture is regulated on an aircraft like the P-47 or P-51? Does mixture have to be adjusted as the throttle is moved, or are there automatic modes for mixture? If there is an automatic mode, how does it work?

Thanks,

John

[Bill Greenwood]

I don't know about P-47, but there is a mixture control on P-51s that the pilot can operate. It has several automatic positions like auto lean, rich or run as well as idle cutoff. The Brits wanted to simplify chores for the fighter pilot, and made it more automatic on their Merlin engine planes. Thus the mixture is not pilot set, it starts lean for idle or economy cruise and it automatically richens as the pilot opens the throttle, above either 44 inches (plus 7 lbs boost) on Spit Mk IX or 46 inches in Mustang III. I wonder how it is done on Mosquito and Lancaster? Mustang owners like Vlado or Mike or Jim would know a lot more. I can't find either of my 51 pilot manuals right now. I think they use auto lean for warm up and taxi, going to auto run or auto rich for takeoff. I know there seems to be a lot of discussion about which to use at the 51 sessions. Us pilots flying British planes don't have that extra control to fidget with which is probably good since we don't have all that much fuel anyway.

[mgeorge51]

In the P-51 the mixture control simply blocks off 1 of the 3 holes allowing fuel into the carb when you go to auto lean. Seems like it should do more then that if you are going to call it AUTO.

In the Corsair forgetting Auto lean in cruise is quite expensive on the fuel flow somewhere around 15 to 20 galons per hour.