Version 15.0
AF-5000 Series Pilot Guide
57
Pitch AXIS Overview
The goal of tuning IAS Hold is to give the AP the best possible pitch axis performance. Crisp speed
control is a prerequisite for good altitude and glideslope control.
The procedure which follows can be used both for initial tuning and for troubleshooting problems which
may arise in your system. Like any checklist or procedure, be sure to follow each step.
•
The ALT bug should be set to an altitude many thousands of feet above or below the
intended flight testing altitude. This is to keep the autopilot in IAS Hold mode throughout
the procedure, and prevent the autopilot from capturing the target altitude.
The Pitch Axis IAS Hold tuning process can be summarized as follows:
Increase or decrease airspeed command by 10 knots, and observe the results. The AP should promptly
change pitch to change speed, and smoothly reach the commanded speed with little or no overshoot
(above the target if increasing; below the target if decreasing).
If the AP is slow to respond to the airspeed changes, increase the PITCH SENSITIVITY and watch for
improvement. In some cases this may require a fair amount of increase, but be cautious about changing
too quickly. Sensitivity adjustments alone may not completely eliminate overshoot. If increasing sensitivity
no longer improves performance, PITCH GAIN may be used to fine tune IAS Hold. Too much sensitivity
may cause AP responses to be "twitchy". Reduce PITCH SENSITIVITY if this occurs. Too much PITCH
GAIN will result in a rough ride.
In particular, if the autopilot cannot keep up with the flight director pitch command bar, PITCH
SENSITIVITY should be increased. At some point the AP will track the command bars, but follow behind
them. PITCH GAIN will reduce the gap.
Summary of Contents for AF-5400
Page 58: ...Version 15 0 AF 5000 Series Pilot Guide 58 Flowchart Pitch Axis IAS Hold Procedure...
Page 60: ...Version 15 0 AF 5000 Series Pilot Guide 60 Altitude Capture Procedure Part 1 of 2 Part 2 of 2...
Page 62: ...Version 15 0 AF 5000 Series Pilot Guide 62 Autopilot Settings Defaults...
Page 73: ...Version 15 0 AF 5000 Series Pilot Guide 73 FREQ Tab RCNT Tab...
Page 88: ...Version 15 0 AF 5000 Series Pilot Guide 88 VFR Sectional Full Screen Mode Split Screen Mode...
Page 89: ...Version 15 0 AF 5000 Series Pilot Guide 89 IFR Low Altitude Chart Airport Diagrams...
