Strange flap issue

[Laury415]

My transmitter is a X20s, and the receiver is a TD-Sr18. I'm using this equipment in a turbine powered jet. Everything has been going good with the jet until today. Before take off I went through normal control surface checks and everything looked good. I switched to take off flaps, took off, flew my flight then put in full flaps for landing. The flaps functioned as they are supposed to but, taxing back I found the flaps would not come back up after I had landed. The first flight only one of the flaps wouldn't come back up, but on the second flight both of the flaps wouldn't come up. When I cycle the power to the jet the flaps will then work up, down, and even half.

I'm assuming the problem is either with my transmitter or receiver because both flaps are independent of each other on their own channels and have independent wiring going to the receiver. It's unlikely that the servos or any of the wiring or connectors are at fault with the exact same problem.

One of the troubleshooting things I thought of on the way home is to change the flap switch to a different switch. If the problem still exists then it's most like the the receiver, if the problem goes away then it's most likely a faulty switch with my radio.

Does anyone have any input or other suggestions of why this might happen?

 

[gnichola]

I would go to "per channel" mode to see what is affecting the flap channels.

In this example you can see that channel 1 is controlled by up to 4 items, and currently it is controlled by Rudder and Aileron.
The thought is that perhaps there is some mix going on that you are unaware of.

 

[Laury415]

Thanks. I'll take a look at that today. I also had a suggestion to look at the logs which I believe I had enabled. They will let me see if the radio was transmitting the correct signal.

One other suggestion was to look at the 2 servos. While it is unlikely, it's possible they both have a lock up condition. All control surfaces servos on this jet came with the jet. They probably are good, but not as good quality or torque rated as servos I would have put in.

 

[gnichola]

I am not sure what you would see in logs. I don't see how it could be a radio issue as you can't really just lose 2 channels while all the others are working. Another big friend of mine is the Outputs page. Flipping your flap switch back and forth should yield a change in both flap channel outputs.

 

[Wayne]

@gnichola - Cool new trick, I'll be using that "per channel" tool in the future when looking at other peoples programming trying to locate the issue. Very nice!

This sounds like a programming issue, but you never know, could be something else going on. But if you have any logic statements as part of the flaps, be sure to study those as they can confuse things. But also make sure the flap servos are not working against an unseen load. Make sure the servos are not heating up, etc.