Mini-X Installation, Setup & User Manual GRT Avionics
Revision A9 79
The alarm function may also be used routinely in cruise flight to give you early warning of unusual
conditions. Limits can be established based on experience, but 50°F is a good starting point.
8.3.4 Fuel Efficiency and Management Tools
Private pilots suffer from a much higher rate of fuel exhaustion accidents than commercial pilots.
These accidents are avoidable, and we encourage the pilot to read this section carefully and develop
good techniques for fuel management. This section provides information about tools for cruise
efficiency and fuel management.
Lean Assist
When Lean Assist is activated, the EFIS first clears its record of peak EGTs for each cylinder. It then
continually stores the highest EGT for each cylinder as the new peak EGT and displays how far each
cylinder is from that temperature. This differential is shown as a negative number above each EGT
bar graph.
To Use this Function for Leaning:
1. Select any engine page. The EGT page is ideal, as the large EGT time history helps you visualize
your progress during leaning. Cylinders are numbered in sequence from left to right.
2. Press the LEAN softkey to highlight the “LEAN” selection.
3. Slowly lean the engine. As you do, the EGTs should all increase. As the EGTs increase, the EFIS
updates its internally-stored highest EGT for each cylinder. As leaning continues, the cylinders
will reach peak EGT and then begin to fall.
4. Once a cylinder has fallen below peak, the value shown on the screen will switch to a negative
number. The first cylinder to peak is surrounded by a white box.
The last cylinder to peak is surrounded by a green box.
5. For operation
rich of peak
, use the first cylinder to peak as the
baseline. After reaching the peak EGT, enrich the mixture back
through peak until the number in the white box is the desired
change in temperature (typically, 50°F rich of peak).
6. For operation
lean of peak
, use the last cylinder to peak (the
green box) as the baseline. After peak, continue to lean the
engine until the desired value below peak is in the green box. A
manifold pressure is highly recommended to enable monitoring of
percent power
to ensure
leaning is not attempted above 75% power, as most engine manufacturers warn against it.
