2 Important Steps Prior to In-Flight Tuning
It is essential for good autopilot performance to ensure the autopilot servos are properly installed
and correctly connected to the aircraft's flight control systems. Poor installation, or incorrect
connection may result in poor performance or safety hazards. Ensure the servos are installed in
accordance with the instructions in the system installation manual. Additionally, the following
steps will help verify the autopilot is mechanically suitable for in-flight tuning.
2.1 Servo Calibration
Prior to any in-flight testing, ensure that the autopilot servos have been properly calibrated. See
the Skyview System Installation Guide document for further information.
2.2 Auto-Trim Calibration
If the aircraft is equipped with electric trim, ensure that the trim system has been properly
calibrated and configured before in-flight tuning. See the Skyview System Installation Guide
document for further information.
2.3 Servo to Flight Control Coupling Check
With the aircraft parked on level ground, and the engine off:
1. Center flight controls
2. Synchronize HDG and ALT bugs to present heading and altitude
3. Engage autopilot in HDG and ALT mode
•Observe autopilot hold the controls stationary.
4. Have assistant manually apply simulated air loads to the flight control surfaces
•Observe servos resist the simulated air loads,
•Flight control surfaces should move very little before servo slips.
If the controls surfaces have significant movement when the simulated air loads are applied
check that the servo mounting bracket is not exhibiting any deflection/bending. Ensure all
interconnect hardware (such as bridal cables or pushrods) are tight and tensioned appropriately.
Any significant sources of slop in the mechanical system between the autopilot servo and the
flight control surface will cause degraded autopilot performance and makes precise autopilot
tuning ineffectual. Acceptable slop values vary depending on aircraft make and model.
Nominally, ±2.5 degrees for ailerons and ±4 degrees for elevator and rudder before servo
slipping is considered acceptable in general cases. If slop cannot be reduced with adjustment of
the flight control system adjust the Lost Motion Compensation setting for the affected axis using
the instructions in Section 6.
