E386 – Auto Takeoff

In this page we will take a look at the Auto Takeoff Way Point. We will see how to set the way point, and where to go from there.

Enter the Flight Plan screen of Mission Planner. Before setting any WP click the Add Takeoff WP button on the right. When prompted, enter the desired takeoff altitude. It is recommended that your takeoff altitude equal that of your surveying altitude.

autotakeoff1

The next prompt will be pitch angle. It is automatically set to the recommended angle for your UAV.

The resulting WP will be shown under the Waypoints bar. Notice there will not be a takeoff WP visible on the map.

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The Takeoff WP will initiate when the E386 is put into AUTO mode. The prop will begin spinning slowly for an amount of time determined by TKOFF_THR_DELAY, where the default is 80 (8 seconds). After this amount of time the motor will be at full power for takeoff and it is at this time that you can throw the plane.

In the Field

Now the Launcher should pick the E386 up and hold it, fully prepared to launch. One hand is placed on the bottom of the fuselage near the camera opening to guide the throw. The launching hand is placed on the base of the tail, with two or three fingers behind the tail below the rudder for stability and maximum power. Use your stronger or throwing arm for this position.

Never put body parts near the propeller when the battery is plugged in!

The Launcher should communicate to the Ground Station Manager that he is prepared for the motor to start. The Ground Station Manager shall then change the mode to Auto, using either the RC transmitter or the actions tab under the HUD. The Ground Station Manager confirms that the mode is Auto. At this point, the motor will begin spooling up over the course of 8 seconds to full speed. The Launcher should wait until the motor has reached full speed before throwing. To launch, it is best to take one step with the opposite leg (left leg for right-handed operators) and to follow through with the launching arm like throwing a baseball. Shuffling or running with the aircraft is dangerous and makes it harder to achieve sufficient airspeed. The Launcher should aim into the wind with a small 10-20 degree incline and focus on achieving higher airspeed rather than altitude with the throw.

It is important that you do not throw the plane before the motor reaches full throttle or the plane will not be able to gain enough speed for takeoff.

During takeoff the E386 will attempt to hold a constant heading until it reaches the takeoff altitude. Once at altitude, it will turn and travel to the second WP.

The E386 has a battery failsafe that will enable at 14.2v. Take off will drain the battery which will drop the battery to a lower value that will stabalize during autonomous flight. Depending on the amount of work put in during take off the battery may drop below the battery failsafe and the plane will be set into RTL. This can cause the plane to spiral if conditions are unideal. We recommend to launch the plane with a battery above 15.8v.