Trio Avionics Pro Pilot - Manual (Page 70)

Trio Pro Pilot Manual 3.8
70
Chapter 16
In Flight Adjustment of Vertical Gain
Altitude Hold Gain Tuning
To optimize the ALT HLD gain setting in your airplane, perform the following steps:
1. With the V NAV servo on, enter the ALT HLD mode in smooth air at your normal cruise speed
after verifying the pitch trim is properly adjusted for level flight.
2. Enter the PREFERENCES SETTINGS menus and select the VNAV GAIN SETS screen.
3. With the aircraft initially straight and level and the H NAV servo OFF, manually execute a turn at
a bank angle of approximately 15 degrees.
4. If the altitude sags more than 30 feet after entering the
turn the system gain needs to be increased. Perform
step 4.
5. Increase the ALT HLD gain by 5 units, then repeat step 3.
NOTE: This gain setting is for smooth air tracking. If you enter turbulent conditions and the altitude
excursions are more than what you will accept, you may increase the gain (clockwise rotation) to
limit the altitude excursion. A setting of between 40 and 60 has been shown to be optimum for
most aircraft tested during flight evaluation. Your settings should be similar.
Vertical Speed Gain Tuning
The VS gain setting will be adjusted while the aircraft is in an autopilot commanded climb. A good
starting point for this setting is to use the factory gain setting and increase it by five (5) units.
If a climb rate of, say, 800 fpm is chosen and the autopilot is stabilized and only climbing at 500 fpm, the
VS gain should be increased. If the system has the auto-trim option it may present excessive out-of-trim
messages during the climb or descent, again indicating that the gain may need to be adjusted.
NOTE: If Auto Trim is installed, set the TRIM SPEED setting at zero for this procedure. This will prevent
the auto-trim from actuating during this testing. Manually trim the aircraft for a reasonable
amount of trim error. "Reasonable" here means that if you disconnected the V NAV servo, the
climb or dive resulting from a trim error would not cause a sharp, excessive transition to a rate of
climb or descent.
To tune the VS gain, perform the following steps: (Should be done in smooth air)
1. With the V NAV servo on, enter the ALT HLD mode in smooth air at your normal cruise speed
after verifying the pitch trim is properly adjusted for level flight. Press the V MODE button to get
to the SET VS screen.
2. Enter a climb rate of 500 fpm and press the encoder knob to initiate the climb. Allow the climb to
stabilize. If the aircraft is not achieving the 500 fpm rate, proceed to step 3.
3. Enter the PREFERENCES SETTINGS menus as
detailed previously and select the VNAV GAIN SETS
screen.
4. Rotate the encoder to get to the SET VNAV GAINS
screen.
5. Press the H MODE button to move the arrow to the VS field.
6. Increase the VS gain by 5 unit increments until satisfactory performance is obtained. The lowest
gain setting that will give satisfactory performance is the best setting.
7. If the gain is set too high, there may be excessive excursions when engaging the VS mode while
in a high rate of ascent/descent climb/dive.