Stratus Tail lock / Spinning.

[ardikashfi]

Hi guys, recently I crashed my Stratus due to tail spins. This is the second crash with the same cause. The first crash was after inverted funnel (4-5 rounds) and all of the sudden the tail came spinning. The second crash was after static barrel roll, the tail start spinning after 4 to 5 rolls. Did anybody ever experience this? What could be the problem?
FYI, both events happen with tail spinning in counter clockwise direction.
Appreciate your assistance.
Note: I'm using GY611 gyro.

Thanks
Ardi

[Caleb Phillips]

I had something similar happen but I never could determine the exact cause. There are a number of things that could have caused it: the TT slipping out, TT breaking, the gears in the tail box stripping/breaking, or even a broken tail control rod. In my case, the boom was super glued into place and did not slip and the tail gears were not stripped. The only things I found were a broken tail control rod, broken TT and jammed up tail gears (the tail box got warped) but I cannot tell which were pre and post crash damage.

Since it has happened to you twice, I would bet that it's a setup issue. Do you know for a fact that your booms were secure? MA makes quality machines and I would hate to think there's something wrong with the Stratus tail system but I did sew Bobby Watts crash a heli because the boom slipped out.

[ardikashfi]

jonphilli,
After the first crash, we also thought it was the tail boom slipped. So, our solution was to secured/screw down the tail boom to the frame. But, even with the above solution similar thing happenned again. After this one, I think I really need to double chk everything and ask for more feedback from you guys. First crash is bad enough, second is worst. And ofcourse I don't want the third to happen with the similar symptom. Appreciate for more feedback. I'll definitely look into all your proposal. Thanks.

Note:
Its a great/best machine to fly, I enjoyed every bit of the flight time. But, its not a good one to crash.... now I'm really feeling it (especially after 2 crashes in a row).

[DavidH]

I would send the gyro and servo in for a check. Maybe even the transmitter. If there is nothing mechanical wrong with the heli. And if definitely sounds like it is not mechanical related. Then it would have to be the electronics causing the problem. Chasing down electrical problems is difficult. If you can borrow another gyro, I would start with the gyro and swap it out.

You say it was spinning counter clockwise. Is that nose going to the left or the right?
Reason I am asking, it is different if heli is upright or inverted.

David

[Caleb Phillips]

I didn't even consider the gyro in my case. Like David said, it would be almost impossible to find out if it is some intermittent problem in both our cases. All I know is that when I get my heli going again, I'm going to definately get Eric, Botos, or someone else to check it out first.

[rbort]

Your 611 servo could be bad. Give full right rudder and watch to see if it sticks and stay there (full deflection) during the ground check.

Had that issue once on my Spectra-g heli, luckily it was during a ground check and I escaped with my feathers that day.

-=>Raja.

[Rada70]

I had something similar. In my case it turned out to be the tail servo. It went bad. I sent it to futaba.

[Caleb Phillips]

Wow, a lot more common than I thought. I just assumed a mechanical failure but it looks like I'll be sending my 611 to Futaba.

[ardikashfi]

David,
Its spinning with nose to the left (left rudder), I assumed due to counter torque effect. I'll try to replace the Gyro/servo as you all recommended. Thanks guys.
Note: I assumed my Tx is fine cause my other helis are flying with no problem.

But guys, just to think about it, why the Gyro/servo failed? How can we chk before its too late? So far on my other smaller helis with GY401, I never had servo/gyro failure before. And I thought GY611 should be better and more reliable. Appreciate if you guys can give me a few tips on how to chk whether the gyro/servo is coming to an end or need to be changed/replaced soon before worst thing happened. Appreciate your valuable feedback.
Thanks for the support.

Rgds
Ardi

[Laurens]

I had this too on a 601 with the servo. It would just randomly stop holding the tail untill one day it just kept spinning.