Mixture Setting on Enroute Climb


#1

Hello everyone.

I have a question regarding the mixture setting when climbing from one altitude to another. For example, say I am flying a C172 at 3000msl and have adjusted the mixture for this altitude. When subsequently leaving the umbrella of overhead airspace, I would like to climb to 6500msl as per my flight plan. What mixture setting should I use when applying full throttle to get to the higher altitude before leaning again once I reach 6500?

Thanks a lot for your help.


#2

For normally asperated engines, you generally takeoff and climb at full rich. As you get above 5000’ density altitude, you lean during takeoff or climb until the engine runs smoothly, but not more. Engine wear due to high temperatures is the key consideration in climb.

If adequate detail isn’t available in the aircraft operators manual, go the the engine manufacturers’ websites to get into the nitty gritty, but the rules above are sound guides.


#3

Ok, thanks! It would be nice to have a working EGT gauge then, instead of just relying on the tach.


#4

It all depends on what your Density Alt is. I have always gone with 3000 as a general rule but sometimes ppl will lean out for takeoff. Pre takeoff checklist “lean for best power”. You can lean the mixture without getting too hot, just watch oil temps. Make sure you climb faster than vy so you you dont over T


#5

if it is a rental then just keep it hammered.

if you own it get a egt installed.

http://img828.imageshack.us/img828/9780/imgresce.jpg


#6

My rule of thumb is on a normal day above 3,000 lean for peak RPM while monitoring your temps throughout the climb. Adjust every thousand feet. If its a typical hot humid summer day here in the midwest, I will do a standing run-up on the runway with full throttle and lean for max RPM as well before I start my takeoff roll. Not sure if that is “proper” but it makes sense to me and I have never had any problems doing it (as far as temperatures are concerned).