Mixture Management - Cirrus SR22 Pilot Operating Handbook

C D
IRRUS ESIGN
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 pres-
sure altitude. Follow the placarded MAX power fuel flow leaning schedule
and information published in this POH. Refer to Section 4, Normal Proce-
dures. 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 oper-
ations 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.
P/N 13772-006
Reissue A
S 7: A
ECTION IRPLANE AND
M
IXTURE
S
YSTEMS
M
ANAGEMENT
7-45