Ac 3.5 landing gear behavior

Just put the 3.5.0 release on my hexacopter. I’m running 2x Tarot ‘small’ landing gear retracts, where the gear is down (deployed) upon powering up the copter (so 1000pwm being sent to the retracts), and retracted when I flick a switch (at 2000pwm). Wirth the release version of 3.5 I am now seeing strange behaviour. When I launch (with gear down (1000pwm) I flick the switch to retract, but nothing happens. I then flick to deploy, and flick a second time to retract and the retracts work perfectly from this point onward. I imagine this has something to do with the latest landing gear changes in the code.

Mine does the same and noticed this since I started using the 3.5 release candidates. Don’t remember which one it started on, but I also assumed that it was due to the landing gear changes made in 3.5. I do like it better than the switch accidentally being in the wrong place on the ground and the retracts try to cycle as it is now a definite double flip of the switch to activate. Once activated, it works fine though.

1 Like

Ok, thanks for these reports.

It should trigger the landing gear to move on the first move of the switch. The problem could just be that if the transmitter switch is already in the deploy position at startup that won’t be sent until the switch is moved… so the pilot would need to move the switch to retract and then deploy again. I think if the transmitter was powered on with the switch in the retract position then the first move of the switch to deploy would make it deploy.

Anyway, sounds like, as expected, we should have a parameter to decide what to do on startup. I.e. deploy, retract or wait-for-pilot-to-move-switch.

1 Like

I’m a little late in the game here, but I’m curious as to which landing gear systems are having this problem.

I have two Tarot multirotor aircraft with Pixhawk flight controllers. I have used these flight controllers with various AC3.5 release candidates. Both are now using AC3.5.0

One aircraft is a 680 Pro with Tarot TL65B44 “Small” landing gear. The other aircraft is a stretched Tarot 650 Sport with TL65S04 landing gear and a TL8X002 controller.

To date I have had no landing gear issues with either aircraft…

Mine is also using the Tarot ‘Small’ TL65B43 retracts, and Powering/Launching with these deployed (1000pwm), the retract only happens on the second operation of the switch (so flick high pwm/2000, low/1000, and high/2000 again).

I tested both of my aircraft, and this is normal behavior. When you think about it, its a good idea…

Its only ‘normal’ this way since 3.5 - before 3.5 it worked differently - what I would consider normal. I simply want to be able to power up my craft with the gear deployed and flick a switch to retract it. Don’t want to have to flick it 3 times to get it to retract - how is this a good idea?


Just for you. :slightly_smiling_face:

1 Like

It’s a good idea because Pixhawk is controlling the gear. You can always go back to direct receiver control, but you loose automatic deployment when Pixhawk goes into Land Mode…

Not sure I understand you @oldgazer1. Why does the fact that Pixhawk is controlling the gear make this a good idea? I understand that I can control the gear directly from the Rx (how I used to do it many moons ago), but now we have control via AP which deploys the gear on RTL/Land etc, which is much better. My copter gets stored with the gear down, so on powering it I simply want to be able to flick a switch to raise it (rather than do this 3 times to make it raise). Looking forward to giving 3.5.2-rc1 a try. Thanks to Randy and the other devs for listening. This community is awesome!

Thanks Randy(@rmackay9), The new landing gear feature works a treat. I have it set to deployed at power-up and works perfectly for my needs. Cheers, Paul

1 Like

Great! thanks for testing! If all goes well Copter-3.5.2 will become the official version in about a week.

Just finished testing the latest beta 3.5.2 for landing gear behavior. Just wanted to let you know it worked perfect for me. I set initial to deploy and now it only takes one flip of the switch to retract. I forgot to try a RTL to ensure they deploy automatically, but will try to get to it later today if possible. I am sure it will be fine. Nice work and thanks!


Tested RTL this afternoon and it deployed the landing gear as expected. Everything seemed to work fine for me. Thanks again.


1 Like

Great, thanks very much for testing! I suspect Copter-3.5.2 will become the official version in a few more days (assuming nothing turns up).

Hi everyone it seems that i am a little late to the thread however i want to share here a couple of thoughts regarding the landing gear operation.

Lately i am setting up a skywalker uav with a pixhawk autopilot for surveying missions mostly, i put on a camera protector that is moved with a servo so the motion can be seem as one landing gear: when the aircraft is in take off and landing the protection of the camera is deployed and when performing the mission is retracted. However since its hard to see this motion of the camera protector i thought if there is a way that, somehow, the mission planner can visualy or by sound confirmed that the needed action took place.

I can explain myself more easily by reminding you about the alnding gear switch on manned aircraft. There is a lever that when you pull it a led confirm that the gear perform the commanded action.

so can this be done?

The easiest way would be to use a simple microswitch that is engaged when your door opens/closes, using the Button feature (

Excuse me Mr but can you teach me how to do it?
Or share with me some tutorial… Thank you very much in advanced

You need to enable it from the full parameter list, then the extra parameters will appear so you can set it up. A simple switch like a microswitch or reed switch will work fine.

Is there some way to do so only on software.

Somehow with a script that based on the servo output status prints a message…

Like “if rc_9> 1400 pwm sent message : landing gear down…”