For Your Safe Flight
Page 15
I2.3
*
Determining the pre-lean value:
while in cruise at under 65 percent
power, choose any cylinder and lean that cylinder to peak EGT in the
Manual mode or to engine roughness, whichever occurs first. Note the
peak, subtract 50° and write the resulting number in the space provided
in step 2.
LeanFind Procedure—General Explanation
Lycoming and Continental engines have established specific
restrictions on leaning that must be followed, such as
percentage of power, climb leaning, and TIT limits. Lycoming
recommends operation at peak EGT for power settings of 75%
or lower, while Continental recommends operation at peak
EGT for power settings of 65% or lower. This guide is not
meant to supersede any specific recommendations of the
engine manufacturer or airframe manufacturer
.
It is your responsibility to know your aircraft’s limitations.
Pre-lean the mixture to about 50° below peak. After pre-leaning, wait for
one minute for the temperatures to stabilize. Next, begin the leaning
process by tapping the
LF
button. This tells the EDM to begin looking
for a 15° rise in EGT for any cylinder. Begin leaning the mixture. When
a 15° rise occurs, eliminating false peaks, the LeanFind mode becomes
activated shown when the cylinder dot above the column of the hottest
cylinder begins flashing.
The LeanFind mode is not active until a
cylinder dot is blinking.
With the Fuel Flow Option, instead of seeing the word
LF
in
the display, you will see numerical fuel flow rate during the
leaning process on the right side of the digital display, for
example
I2.4
. This allows you to observe the EGT rise and at
the same time watch the fuel flow rate decrease.
To show the progress of the leaning process, the EDM selects the hottest
cylinder for reference in the digital display. In the example below, the
I360
is the current temperature of the hottest cylinder.
