The MFD is equipped with a lean assist function which is used to set the optimum
mixture for various operating conditions. The MFD will automatically detect whether
the pilot is leaning for best power or best economy and provide visual messages to
guide the pilot toward the correct mixture setting.
Leaning for Best Economy
1)
In order to lean the engine for best economy, begin by pressing the “Lean Assist”
button and smoothly lean the mixture control. Best Economy leaning should only
be undertaken at power levels below 75%.
2)
The MFD will annunciate "Looking for 1st Peak" at the top of the temperatures
section of the display.
3)
As the EGT’s rise, the first cylinder will reach peak EGT and the MFD Engine Page
will annunciate “Best Economy,” indicating that the best economy mixture has been
achieved. Due to EGT variation, the MFD may occasionally detect a false peak
and annunciate "Best Economy," even though the EGTs continue to rise.
4)
If the mixture is leaned too far to the lean side, past the Best Economy setting, the
MFD shall annunciate “Too Lean.” The pilot should slowly enrichen the mixture
until the annunciation switches back to “Best Economy.”
5)
After the desired engine lean setting is achieved, press the “Normalize” or
“Absolute” button to exit the Lean
Assist function.
The Lean State is also displayed in the
“Lean” datablock on the Map Page.
Engine Instruments - Lean Assist For Best
Economy (Saratoga II HP& Piper 6X)
FlightMax EX5000
-18-
600-00105-000 Rev 01
NOTE: It is very important to adjust the mixture slowly and continuously.
Leaning the mixture too quickly could disrupt the MFD’s ability to accurate-
ly track the peak EGT, and could result in a mixture setting damaging to the
engine. Always be sure to monitor Oil Temperature and CHT readings, to
ensure they stay within specified limits.
CAUTION: If at any time during the Lean Assist process the engine begins
to run roughly, richen the mixture slightly until the roughness abates.
NOTE: If the percent power display is not availabe, consult the aircraft POH
performance charts to determine current aircraft percent power prior to
engine leaning.
