test in air elevator

[richard in australia]

Hi people,

Today i turned off my Tx mid flight to test auto pilot for first time which resulted in one very big crash. Later I went into RVOSD and discovered that test in air elevator was set to OFF.

I'm assuming thats why the plane banked nicely in RTH mode but then kept banking and pitched nose first into the ground before I could re-activate radio and pull out of the dive.

Am I right? Should it be set to ON for auto pilot to work properly with both ailerons and elevator?

Regards Rich.

[Alex Villa]

The menu If R/C link lost Have the option to do test in the air of rudder and elevator separatly, by activating them with the auxiliary switch just the same you activate//deactivate Stabilization modes on full autopilot.
So If Test in the air is selected on the menu IF R/C link lost then you can use the auxiliary switch to test rudder or elevator control only. On this case you have to activate Test in the air elevator to make it one of the options to be cycled by the auxiliary switch.
Notice that I sugest on the instructions to test the autopilot at enough altitude to recover from wrong settings.
A video of the flight will be very helpfull to know whats the problem here. Do you have have the IR sensors activated?

[richard in australia]

Thanks, but I'm still confused, yes I have IR sensors and yes I have video of crash. I will reply again with the video later today.

Thanks Alex

[Alex Villa]

If you have the IR sensors installed, and the AHI is working properly, then this could be a problem of wrong servo directions on the autopilot settings.

[richard in australia]

Hi Alex, please see these 2 videos. One of crash and the other of menu setup and I would really appreciate your thoughts,

Regards, Rich

http://www.youtube.com/watch?v=avc--uWTUpE
http://www.youtube.com/watch?v=H1LiSCXMm1g

[Alex Villa]

Ok the video of the crash told me all. Roll servo direction was inverted. So when the autopilot tried to correct roll, everything went crazy.
This should be set on the R/C wizard if you follow the wizard instructions properly and save configuration after running it. But you can also change it direct on the menu.

Another mistake was to test the autopilot at 80mts. I usually do it at 200 mts. This way I have more time to recover.

[richard in australia]

Alex, please look at second video (I know you are a busy man , but maybe the answer lays there) yaw/roll servo direction are set to normal. The problem from the video was that there was no elevator - the ailerons seemed to work fine. I ran the wizard before flight as suggested. I realise that diagnosis is difficult from your end using the info I have provided but please look at second video because I am at a loose end and feel that the answer may lay there. Please be patient with me... the first half of vid is using the remote control (RVOSD remote pad) and then menu is gained thru Tx switch. Rich ps I am limited to 400 feet as there is an air field 5kms away and that is my legal limit

[Alex Villa]

I watched both videos, and this is all I can tell from them. If you post a more detailed video navigating screen AP 3/3 I could tell if the servo directions are good, by watching the servo direction indicators while you change menus up and down and modify menus itself. Notice that next to servo directions, actual stick movements are displayed.

Ther is another way for you to test the autopilot on ground. This is:
-Remove airplane propeller, and set the plane leveled
-Put a cup of warm water under the Z head(sensor facing down). Not to warm but just warm enough to set the AHI to indicate plane upside.
-Move your hands around the XY sensors to level the AHI.
-Activate autopilot in level flight mode and simulate AHI movements by moving hands around the sensors.
-Watch that surface control movements do the appropriate corrections to keep the plane level with the cheated AHI.

My bet is that you will find that roll control is reversed.

[richard in australia]

Thanks Alex, I assume you mean page 3 of 3 of the autopilot menu. I'll work on that tomorrow but for now I have to go to bed... it's 4am in Australia right now... and i still have an entire plane to rebuild.

Thanks again, Rich

[Alex Villa]

Yes, thats correct. Autopilot menu page 3 of 3. Good nights .