Mixture Management - Cirrus SR22 Pilot Operating Handbook

Section 7 Cirrus Design
Systems Description SR22

Mixture Management

The mixture control needs to be carefully monitored and managed
during all phases of flight to avoid damage to the engine or a possible
loss of power.
After engine start, and during taxiing operations, lean the mixture until
maximum engine RPM is attained to prevent possible spark plug
fouling and ensure smooth engine operation.
Takeoff and climb fuel flows need to be set appropriately. During
takeoff, the mixture can be set to full rich when below 5000 feet
Density Altitude (DA). For conditions where takeoff performance is
critical, such as high density altitude operations (greater than 5000
feet DA), set the mixture to the fuel flow schedule that is placarded in
the aircraft and published in this POH. Refer to Section 4, Normal
Procedures. Fuel flow should be set to the top of the green arc on the
display. EGT's should generally be at least 1200 °F at full power.
During climb, it is necessary to lean the mixture to achieve maximum
power. An excessively rich mixture and a slightly rough-running engine
will occur if the mixture control is set to FULL RICH above 7500 feet
pressure altitude. Follow the placarded MAX power fuel flow leaning
schedule and information published in this POH. Refer to Section 4,
Normal Procedures. If CHTs or oil temps become higher than desired,
using a slightly richer-than-placarded fuel flow will aid in engine
cooling.
During cruise flight, the throttle should be set for 75% power or less
when operating the engine at best power mixture settings, and 65%
power or less when operating at best economy mixture settings.
During best power operations the mixture should be set for 75 °F rich
of peak EGT. During best economy operations the mixture should be
set to 50 °F lean of peak EGT.
If a cruise power descent is used, it is necessary to richen the mixture
to maintain EGT's at approximately 1200-1400 °F during descent. If a
reduced power descent is used, it is still necessary to richen the
mixture to prevent an overly lean condition when power is added.
During approach and landing, the mixture should be set to the position
that will result in obtaining the placarded full throttle fuel flows if the
throttle were advanced to wide open.
7-50 P/N 13772-004
Revision 1