Section 4
Columbia 400 (LC41-550FG)
Normal Procedures
Initial Issue of Manual: November 10, 2004
RC050002
Latest Revision Level/Date: -/11-10-2004
4-29
flight. Section 5 in this manual contains detailed information to assist the pilot in the flight
planning process.
In general, the airplane cruises at 50% to 85% of available power. The maximum recommended
cruise power setting is 85%. The minimum cruise power setting is 40%, but higher power
settings may be required in colder weather to maintain minimum engine temperatures.
Mixture Settings –
In cruise flight and cruise climb, care is needed to ensure that engine
instrument indications are maintained within normal operating ranges. After reaching the desired
altitude and engine temperatures stabilize (usually within five minutes), the mixture must be
adjusted. The engine is equipped with an altitude sensing fuel pump which will automatically
make some mixture adjustments for altitude effects, however additional adjustments may be
required.
Control by Turbine Inlet Temperature (TIT)
–
When leaning the mixture using TIT, the pilot
should use the aircraft’s TIT gauge on the left hand kidney panel as primary. Be aware that the
TIT displayed on the Avidyne MFD Engine page, under certain conditions, may indicate a higher
value. If this occurs the pilot may wish to use the most conservative (higher) number for leaning
the engine. At power settings below 85% power, starting at full rich mixture, lean slowly while
observing the TIT. When changing the mixture to lean of peak, it is acceptable to have TIT
indications temporarily in the yellow range, but indications must return to the normal range upon
leaning completion. Best power is obtained at 1650ºF. Above 65% power, the engine must be
operated rich of peak to avoid exceeding the TIT limit. Below 65% power the engine can be
leaned past peak and be operated 50ºF lean of peak TIT. Lean of peak operation improves the
efficiency of the airplane and provides about 30ºF lower CHT at the same RPM/MAP
combination. Fuel flow can be used as a reference to judge the resulting power setting, but
should not be used for leaning.
CAUTION
Do not lean the engine when operating above 85% power. At power settings
above 85%, the mixture must be full rich. Do not lean the engine during
climb.
CAUTION
To prevent detonation, when increasing power, enrich mixture, advance
RPM, and adjust throttle setting, in that order. When reducing power,
retard throttle, then adjust RPM and mixture.
CAUTION
When leaning the mixture, it is acceptable to have TIT indications
temporarily in the yellow range to detect peak. Once leaning is complete, the
temperatures are in the normal range.
WARNING
Continuous overboost operation may damage the engine and require engine
inspection.