Horizon Hobby Carbon Cub S+ flew out of sight never to return

[ronb742]

Today was supposed to be a great day with my son as we finally were able to put the Cub on floats (the float kit that was supposed to fit did not have the right size propeller to fit the shaft). After I engaged the A/P, making sure it had a good GPS lock, we practiced taxiing it around, with my son getting some practice as well. Finally I hit the throttle and she took off in about 10 yards, very impressive. I did a climbing left turn and was establishing my pattern when the plane simply stopped responding to my control inputs. At first I was nervous but then I remembered that I was in Mode 0 (beginner mode) and that the virtual fence should kick in. It didn't. The plane kept climbing and flew about a quarter mile until it turned around. I was very nervous at this point and relieved when I saw it headed back towards us. It performed a check turn away, descended below the tree line, never to be seen again after searching for it for a few hours. Fortunately there is a large uninhabited area with tall trees that hopefully caught the plane. I have no idea what happened. It clearly had GPS as it was maintaining level flight. I read through the instruction booklet and it confirmed that even if it lost transmitter signals, it should have returned to where I initialized the home point.

Any ideas what happened? Any chance Horizon Hobby will refund/replace my plane?

[F22trainer]

“After I engaged the A/P, making sure it had a good GPS lock, we practiced taxiing it...”

If by this you refer to “A/P” as an “auto pilot”, this is a problem. You don’t specify knowing what virtual fence mode it was in. Sounds like it was off - the GPS can still work without a virtual fence mode active.

There is no “auto pilot”, despite several features that make it appear as such. I have this airplane and know it quite well. While the Flight Modes do make it easier to fly, they can also get you in trouble under anything less than ideal circumstances. For example, if you attempt to takeoff in Beginner mode with a crosswind - there will not be enough rudder to compensate for the weathervane and torque (p-factor), and assuming you are using proper up elevator to keep the tail on the ground to properly steer until nearing flight speed. The plane will accelerate and weathervane - not good if you are at an airfield with a barrier (dead line) or a confined area or obstacle.
None of the features have the ability to avoid any obstacles. Activating the “Hold” mode would have returned it to the initialization point.
You did not mention attempting to use this or the auto land, which would also return the aircraft.
I recently assisted a young man and his father to fly their Cub and familiarize them with the auto functions. The father was quite determined to guide his son to use these “safety features” in learning to fly, and they had already had considerable problems before they sought help. After my assistance and explanations, the son soloed on his second flight without any of the features and the GPS deactivated, and not only was father quite proud, but so was mother as she had come to watch as well. Once both knew how to operate the aircraft properly the features became what they were intended for - something to fall back on. But you have to have them set up correctly and test them in controlled flight.
I will add, it is one tough bird and short of a vertical impact it should be easily repaired. Then, find an experienced helper.

[xviper]

You've left some details out that may be important. Did you have the RTF or BNF version? If BNF version, did you program all the switches correctly? Did you read ALL of the manual? There's a lot of information in that manual. You say you "engaged A/P". I don't have this plane but I've dealt with planes and have friends who have this sort of device on their planes but skimming over the manual, it says nothing about "A/P - Auto Pilot". There is always some form of stabilized control (in 3 different modes/level of control). Then there's the "Traffic Pattern - Autoland" feature which is activated with the bind button. What do you mean when you say you "activated A/P"? Did you mean you had the bind button pushed the whole time? This would deactivate the sticks and you have no control.
Did you do the compass calibration? If you had it on "large" virtual fence, that's 1/4 of a KM and to an inexperienced eye, that could look like 1/4 mile. In any case, it looks very far away.
You also said you were taxiing around for a while and then let your son taxi it, too. From the time you hooked up the battery to when the plane "went away", how long was this in minutes? A plane like this on a 2200mah battery could have power for maybe 10 minutes (less if lots of power was used) and much less if you were using the 1300mah battery. Did you set a timer? If you drained the battery, the plane would simply lose power and continue it's way to the ground.
I doubt Horizon will give you a new plane but you can always ask. The circumstances of this "mishap" is somewhat sketchy, based on your description that you've provided here. Simply not enough details for Horizon to establish that it was the fault of the product. They would expect to get every detail of exactly all the things you did from the moment you opened the box to when you lost it.

[rifleman_btx]

Does this one have a compass like the sportsman s? If so did you do the calibration for it? That's the only other idea I can come up with.

[F22trainer]

Does this one have a compass like the sportsman s? If so did you do the calibration for it? That's the only other idea I can come up with.

Yup

[MikeT]

Contact Horizon and explain the situation. They should stand behind it. I was setting one up for a guy and it just didn't want to lock up after numerous tries.Contacted Horizon Support and we were doing it correctly. Horizon stood behind it and the guys ended up with a Apprentice. IMO this CUB just has too much stuff going on for the new flyer.

Mike

[TiredIronGRB]

I have one of these and love it...I disconnected the GPS module and then re-bound it so I don't have to go through all the home setting and such. Safe and AS3X still work fine.

[Gilatrout]

I had his happen on mine. I had one of the very first sold. Total flyaway. I rigged mine with FPV and I could clearly see that the problem was with the virtual fencing algorithm. In my case the GPS signal must have been suppressed long enough for me to get on the far side of the virtual fence. Every attempt I made to manually return to base, I would hit the fence and it would veer away. When I hit the panic return and land it started back, hit the fence and then veered away and would not surrender control of the aircraft back to me. Total loss.


I reported the problem to Horizon, not expecting a refund because of my FPV mods, because it was clear that something was screwed up in the way they did the fencing. I speculate that they must be making the fence line as a value derived from the base location. Not a distance from base, but instead a coordinate line. Approach the line from any direction and the plane will turn around and fly the opposite way. Which would be fine if you somehow didn't end up on the wrong side of the fence. In that case, you can never get home again. Horizon never confirmed or otherwise said this was what was happening. It is just my speculation based upon my single experience with the aircraft.

Horizon, to their credit, refunded my money

[fhhuber]

Sounds like something that could be changed in software to If distance > XXX then head home instead of if distance = XXX turn around.

[F22trainer]

GPS can be cancelled anytime in flight, and doing so will disable any of the virtual fence options, hold mode, and auto land. The flight modes for beginner, etc. remain available. There are 4 virtual fence options but none actually return the airplane. The airfield option will remain on one side of the designated flying area - which must be selected prior to flight in that mode. If GPS is lost in flight the pilot would have to manually fly the aircraft and land. If radio signal is lost and a virtual fence mode is active, it would return to home and hold, depending on the fence mode.
I always allowed the GPS to initialize, and then disabled it. I actually never used the “rescue features” until I just wanted to try them out for fun, being fully prepared to take control if I did not like what was happening.
I would agree it is not the ideal aircraft for a beginner, as it is easy to take flight unprepared. Doing range checks and thoroughly reading the manuals helps, but I’ve seen several good experienced RC pilots nearly lose an aircraft “trying to help a novice” but we’re unable to take control of the plane when certain “auto functions” were active and they did not know how to disable them. One poor guy was in a panic because he could not make the nose point down and could only descend with a reduction in power...it was doing what it was supposed to in Beginner mode. He was stunned when I suggested he try Intermediate or advanced mode, and then demonstrated how they worked. He thought the control surfaces were out of adjustment. He had tried to trim in Beginner mode and was not getting the usual response. Really made him feel awful trying to help a new flyer - the same father son pair I wound up assisting.
I was able to fly an RC plane before I maiden flight this bird and quickly realized that some of the “special features” were hindering my control inputs, but with good intentions. I had to use Intermediate or Advanced modes to override or disable the controller.

[ronb742]

Thanks for the replies, let me provide more detail now that I have some time. First, this is the RTF model with the transmitter included in the kit. I've flown several times before with this aircraft and have played around with the Virtual Fence (I've only used the default setting), the Holding Pattern mode, and the AutoLand Mode. I really enjoyed this plane as I get to fly in the Experienced Mode and then hand it to my son who flies in the Beginner Mode. I did mistakenly call the HP/AL button the A/P button. Yes that would be a problem if I thought it had Auto Pilot. My sequence for this mishap event was this, I turned on the transmitter, powered up the aircraft with a fully charged flight battery, then held the HP/AL button until all the control surfaces wagged, indicating ready for flight. I do not remember if I let the elevator move quickly and then center to indicate GPS lock before I set the home location. Does this impact the aircraft? I taxied for a about a minute in the water to see how it handled with the floats and then had my son taxi for about 2 minutes before I took off.

I applied full power and the plane took off as described earlier. I turned the aircraft around to downwind and tried to turn it to base leg while still climbing. The plane failed to respond. I had no control with the transmitter. I hit the HP/AL button to activate the HP mode but nothing happened. I was getting worried but expected the Virtual Fence safeguard to bring the plane back. The entire time I was trying to manually fly the aircraft. The plane kept heading away. It finally turned back around but still did not come within 100 yards of us and disappeared. I am reading through the manual now and I don't think I could have deactivated the GPS in flight because I did not cycle the flight mode switch 3 times. I did fail to do a range check prior to the flight but the manual also says if at anytime the aircraft loses radio connection, the aircraft will activate Holding Pattern mode. My main concern, as some of you had mentioned, is that I was trying to manually fly the aircraft the entire time but it failed to respond appropriately, then even the expected auto features failed to perform.

I hope this sheds more light on the event. Please let me know if you see something I could have done. I'm certainly not ruling out operator error.

[F22trainer]

After the aircraft is powered up, you need to turn it right side up and stationary to allow the GPS to initialize (wait for the tones after elevator cycles before moving it). Once that is done you can taxi in pulse mode to the runway or home position. Now, that said, while the GPS is initializing ( elevator cycles until the tones) that is when you would hold the TX sticks in the proper position for a desired Virtual Fence Mode. (Large or small circle, flying field, or off) This would allow the use the HP and AL functions with VF disabled.
Once taxi out you would need to hold the HP/AL and wait for the aileron wag, if you have airfield Mode you would also need to hold the aileron stick left or right (determines the flying side of the runway) to complete the startup and enable the throttle. I know it says not to attempt to fly under the Virual fence in airfield mode, and I think you may have inadvertently done so by not knowing if Airfield Mode was in use, though I do not really know what would happen.
If GPS is active, it is cancelled by pushing the HP/AL AND moving the FM switch up and down 3 times - then the rudder will wag 3 times to let you know it is disabled. The FLight Modes are still available.
Any luck finding the airplane? Maybe a friend with an FPV drone or helicopter could help.

[Th3Ed1t0r]

I have one of these and love it...I disconnected the GPS module and then re-bound it so I don't have to go through all the home setting and such. Safe and AS3X still work fine.

Could you be more specific regarding the disconnection of the GPS Module? I find no use for it as well and am planning to remove it, but I'm afraid I might do something wrong that would cause the plane to go haywire on me.

Also, since the GPS has been disconnected, does that mean you now have 1 vacant channel for flaps?

Thank you!

[TiredIronGRB]

The GPS module has a twisted cable coming out of it, it’s best just to go ahead and remove the module and you can see where it connects. There is a spot on the regular receiver for flaps, once you remove the GPS module you will need to re-bind.

[Vtaylor1]

This just happened to me with the same plane. The first time it just went full throttle climbed straight up to over tree line and flew away I had no control. It turned around and came back by itself. It wag when it got back to virtual fence and I had control again. The second time that happen today it did the same thing full throttle went to like 200 feet and flew away. This time it never returned. There is something odd with this plane. We have two other people in our club who has this plane and it did the same thing. Both of theirs returned. I know of four fly aways.

[Traveling Man]

I have one of these and love it...I disconnected the GPS module and then re-bound it so I don't have to go through all the home setting and such. Safe and AS3X still work fine.

Is yours an RTF or BNF? I have the RTF, but was wondering if it was possible to do what you describe.

[Traveling Man]

This just happened to me with the same plane. The first time it just went full throttle climbed straight up to over tree line and flew away I had no control. It turned around and came back by itself. It wag when it got back to virtual fence and I had control again. The second time that happen today it did the same thing full throttle went to like 200 feet and flew away. This time it never returned. There is something odd with this plane. We have two other people in our club who has this plane and it did the same thing. Both of theirs returned. I know of four fly aways.

Damn, now I am getting nervous about flying mine. Not least because it has to come down somewhere, what if it hit someone.

[Vtaylor1]

It a very wooded area beyond our field. If it got two three miles away it may end up in a corn field and a couple of houses yards. I went there nothing was there. But you r right. I have read other blogs where the GPS module breaks. Causing this. I am on east coast time and will call horizon hobby today and ask.

[F22trainer]

Damn, now I am getting nervous about flying mine. Not least because it has to come down somewhere, what if it hit someone.

The important thing here is you cannot think for one minute this is something anyone can do - you need to get help for someone that knows the airplanes. Once you crash - you have no idea what internal components may have been damaged. This hobby is dangerous- period. The AMA can offer some help with clubs in your area.
GeT help and an Instructor or you will crash.
If you hit someone or damage their property, you are liable.

These planes work just fine if you follow the directions and take the time to understand the steps and how the features work - and there are many excellent videos to help, but you cannot just open the box and go.

[xviper]

Is yours an RTF or BNF? I have the RTF, but was wondering if it was possible to do what you describe.

I believe you can. I think the GPS module can be "unplugged". Then you must know how to bind it again. Look at the instructions for binding on the BNF version. It should say something about it in your manual.