S
ECTION
4: N
ORMAL
P
ROCEDURES
C
IRRUS
D
ESIGN
N
ORMAL
P
ROCEDURES
SR20
4-20
P/N 11934-005
Cruise Leaning
• CAUTION •
If moving the mixture control from the full rich position only
decreases the EGT from the full rich value, place the mixture
control back in the full forward position and have the fuel system
serviced.
Exhaust gas temperature (EGT) may be used as an aid for mixture leaning
in cruise flight.
• N
OTE
•
Engine can be leaned for Best Power Cruise at any power setting.
For Best Economy use 75% power or less. For best durability, use
85% or less at best power.
To adjust the mixture, lean to establish the peak EGT as a reference point
and then adjust the mixture by the desired increment based on the
following table:
Alternatively, leaning can be done by adjusting the mixture to the cyan
Target Fuel Flow caret displayed on the fuel flow gauge.
Target Fuel Flow is determined using a calculated engine air flow based on
engine speed, manifold air temperature and manifold air pressure.
Target Fuel Flow is advisory only and does not guarantee sufficient cylinder
cooling. If any CHT's are greater than 435 °F enrich the mixture to aid in
cooling. Under some conditions, engine roughness may occur while oper-
ating at best economy. If this occurs, enrich mixture as required to smooth
engine operation. Any change in altitude or Power Lever position will
require a recheck of EGT indication.
Mixture Description
Exhaust Gas Temperature
Best Power
100 °F Rich Of Peak EGT
Best Economy
Between Peak EGT and 50 °F
Lean Of Peak EGT, depending on
ambient conditions
Reissue A