ALTA Pro will notify the pilot of critical alarms through QGroundControl. These alarms indicate a serious issue has been observed in the behavior of the ALTA Pro that, if not acted upon immediately, can cause loss of control. Never continue a flight when ALTA Pro indicates an alarm!

Flight Controller Modes

Overview

ALTA Pro has three primary flight control modes which are selected using the Mode Switch: Manual Mode, Altitude Mode, and Position Mode. ALTA Pro also has two emergency control modes, Return-to-Land and Autoland, which are available only during certain situations. For additional information, refer to the sub-section associated with each emergency control mode.

Manual Mode

In Manual Mode, ALTA Pro will only stabilize its attitude. At neutral control input (middle pitch and roll stick position), ALTA Pro will attempt to remain level. Throttle control is direct.

Altitude Mode

Altitude Mode changes the throttle stick behavior to command climb and descent rates. The higher the throttle stick position, the faster ALTA Pro will climb. Conversely, the lower the throttle stick position, the faster ALTA Pro will descend.

When the throttle stick is centered, ALTA Pro will enter Altitude Hold. In Altitude Hold, ALTA Pro will maintain a target altitude and try to correct for drift. If a disturbance moves ALTA Pro away from this target altitude, ALTA Pro will climb or descend to return to the target altitude.

Position Mode

Position Mode changes the pitch/roll stick behavior to command ground speeds. Pitch and roll stick deflection will command fore/aft and left/right ground speeds respectively. Controlling altitude in Position Mode is the same as in Altitude Mode.

With pitch and roll controls centered, ALTA Pro will enter Position Hold. In Position Hold, ALTA Pro will maintain its position over a given point on the ground and correct for disturbances.

Position Mode requires a strong GPS signal and communication with a minimum of 6 satellites. If a weak signal is present, ALTA Pro will not enter Position Mode. If the GPS signal degrades while in Position Mode, ALTA Pro will automatically revert to Manual Mode.

Within Position Mode ALTA Pro enters Classic Control style which use the tuning parameters to control translational position over the ground.

Waypoints Mode

Waypoints mode allows ALTA Pro to execute a predefined autonomous waypoint missions that have been uploaded to the flight controller via ALTA Pro QGroundControl (QGC). For more information on all of the different options and abilities built into the Waypoint functionality you can read more in the PX Literature.

Return-to-Land

Return-to-Land Mode will command ALTA Pro to fly back to the defined Home Point. When ALTA Pro first acquires a GPS position, it sets this as the Home Point of the flight. See the Radio Channel Mapping section in this manual for more information on setting up the Return-to-Land Switch.

RTL can be initiated automatically with an LOS event if it is selected as the Signal Loss Action in the ALTA App. RTL can also be initiated manually while flying in Position Mode and setting the Home Switch to RTH.

When initiated manually using the Home Switch, ALTA Pro will fly back to the Home Point. ALTA Pro will hover above the home point and wait for a set amount of time and then land. The pilot can cancel the RTL procedure by returning the Home Switch to the middle or bottom position.

During an LOS event, RTL followed by Autoland will be initiated automatically if ‘RTL’ is selected as Signal Loss Action in the ALTA App and an S.Bus/S.Bus2 or DSM2/DSMX radio system is in use. ALTA Pro will first check its current altitude against Safe Height. If ALTA Pro is below the Safe Height, it will climb to Safe Height. If ALTA Pro is above Safe Height, it will remain at its current altitude. Next, ALTA Pro will fly back to the home position at the RTL Speed set in the ALTA Pro QGroundControl. Finally, upon reaching the home position, ALTA Pro will loiter for 15s and then begin to Autoland.

Autoland

Autoland will only initiate if one of the following conditions is met and the Autoland is setup as the failsafe for these events. See the Safety Parameters to customize ALTA Pro’s failsafe behaviors:

• Loss of Signal (LOS) occurs and ‘Land’ is selected as the Signal Loss Action in the ALTA app

• At the end of a LOS Return-to-Land event when using S.Bus/S.Bus2 or DSM2/DSMX radio systems

• Battery exhaustion failsafe is tripped and the failsafe is set to return to land in ALTA Pro QGroundControl.

Geofences

Geofences are currently not supported by Freefly. We recommend that you do not use this feature. If this feature is used, set the Geofence breach action to Warning; Hold, RTL, and Terminate should not be used as they may result in crash or an ALTA Pro that cannot return to its home position.

The home switch has three positions, however only the top toggle position will turn RTL on.

RTL Off

(Bottom/Middle Toggle Position)

This is the normal switch position and does not initiate an RTL command.

RTL On

(Top Toggle Position)

This manually initiates the RTL function. In RTL, PX4 will command ALTA Pro to climb to the set minimum altitude and then guide the unit’s position to the home point.

The rear-facing Status Light shows the status of ALTA Pro as it boots, arms, and flies. The following table shows the different meanings of the light in the various flight phases.

ALTA Pro automatically logs flight and control data when ALTA Pro is armed for flight. Data is recorded to the autopilot and are accessed through the Log Download tab in the Analyze menu of ALTA Pro QGroundControl.

Summarized flight data from an individual flight can also be viewed immediately after landing by placing a downloaded log file into PixHawk Flight Review. Full details about the review process can be found in the Flight Reporting section of the Pixhawk User Manual.

A native data analyzer is being developed and will be available on the ALTA Pro Support page.

ALTA Pro QGroundControl includes a flight status monitor that displays information about the health of the ALTA Pro and the various controls that can be selected.

The boom-end mounted Orientation Lights indicate both the orientation of ALTA Pro in flight and the status of the individual motor Electronic Speed Controllers (ESCs) during other operational phases. The following table shows the different meanings of the light colors in the various operational phases.