Flight Level Change Mode (FLC)
1) Select the desired altitude by turning the ALT Knob to set the altitude in the Altitude Select box. This altitude must be selected ﬁrst because Flight Level Change mode will only ﬂy toward a selected altitude.
2) Press the FLC Key. The flight director is activated (if not already active) and 'FLC' is now displayed in green in the Active Mode ﬁeld and the Airspeed Bug will appear on the Airspeed Indicator. Pitch commands are given to manually maintain airspeed. Press the AP Key to engage the autopilot for maintaining the current airspeed. Altitude Hold mode is automatically armed with 'ALT' displayed white in the Armed Mode ﬁeld to the right of the 'FLC' annunciation.
3) The Airspeed Bug can be adjusted in 1 knot increments by pressing the NOSE UP/NOSE DN Keys to set the desired airspeed. The airspeed setting will be displayed in the Selected Airspeed box above the Airspeed Indicator and in the Airspeed Reference ﬁeld in the AFCS Status Bar.
4) Airspeed may also be changed by pressing and holding the CWS button to manually establish the desired airspeed using the control wheel. When the CWS button is released, the currentairspeed will be maintained.
5) The most important: Adjust engine power to allow the autopilot to ﬂy the aircraft at a pitch attitude which corresponds to the selected airspeed and the desired ﬂight proﬁle (descent or climb). You have to change the throttle power by at least a bit to start/activate the climb or the descent. Slower to descent, faster to climb.
6) With Altitude Hold mode armed, as the selected altitude is reached, 'ALT' will ﬂash in green for 10 seconds in the Active Mode ﬁeld, after which the annunciation stops ﬂashing. This signals the altitude capture is complete and the selected altitude will be maintained at the selected airspeed. If only the ﬂight director is engaged, pitch commands are given to manually maintain the selected altitude.
I recommend you try this procedure with my Baron G58 with G1000 and Avitab Integration.