Glitching or lockout???

[Degzie]

Hello Guys.

I have a Fury Tempest, closed tail box version, been flown for around 8 months, originally it had an OS-91 C spec installed but it used to stop after around 8-10 minutes of flying, I changed it for a YS-91ST & that did the same thing only the once though, then flew for another three months, no problems.

I then installed a duralite 4000mah pack & a 5.3v regulator, no problems there, I had a CSM 560 gyro & a JR 8700G servo, they never would work so well, so I swapped them out for a GY611 & everything seemed fine for the next few flights.

OK now the machine flies for around 6-8 mins and then the three servos (JR DS8511) controlling the swashplate "jump". From what I have seen the helicopter do in the four times it has happened is that the three servos & only these (throttle OK, steady rpm & tail OK, constant heading), was to cause the heli to descend as if I had lowered the collective rapidly then after a slit second just before impact they spring back to life, I land & then collapse, from too much adrenalin, it hasn't crashed yet, also noteworthy is this heli has never been crashed.

Last time it happened was when the heli was hovering at about 10ft less than 8 meters away from me, I got a good close look at what happened, It just dropped so fast like I lowered the collective & then recovered at about 1ft, back into a stable hover, OH MY GOD, I landed & wondered what the hell.

I have tested the voltages for the duralites, the wire harnesses for the servos have also all been checked, It could I suppose be the RX (35mhz JR 649 PCM, set to FS), it could be a bearing, or well I don't know..........?

One interesting thing though, I have a throttle jokey pro installed & it was set to normal servo mode now after the last episode it is in super servo mode, could this be my problem?

That is where you guys come it, suggestions please, I will post the results, so thanks in advance.

[H to the C]

check the wires on your switch and regulator. I had a chopper not long ago do the same thing during flight. It would not do it while sitting on the ground not running. But as soon as you started the engine up and got to lift off headspeed it would do this.

Turn on your heli and radio and wiggle the wires all around on the switch and the regulator. I kinda got a feeling this "MAY BE" the problem.

Wiggle the heck out of them....

hope this helps
hc

[Beast]

Degzie just curious where is Dubai? Anyways not sure what radio you are using but if it's the futaba radios, i have seen the pots on the sticks go bad and since it is ccpm, if the throtle/pitch pot go bad it will do just that the headspeed would however stay the same since the gov takes over control of the trotle control. hope this helps

[Dr.Ben]

RE what Henry said, the first thing to do is completely remove the reg system and see if the problem persists. Intermittent power from a reg can be particualrly dangerous b/c it can cause the gyro and receiver f/s to reset if it occurs in flight. There's a whole lot of added complexity there just waiting to go ary (and no, I'm not anti reg; I use one myself). Next, make sure you have you radio's F/S set to go to idle AND to cut the governor OFF. If you have a true HOLD condition, the engine should drop back to idle. Beast's suggestion about bad pots can be REALLY tough to ID. I had a tranny that would only do it when the temps were under 45D. I had to sit in a cold garage cycling the collective up and down slowly over several sessions before it FINALLY acted up. Of course, you need to do the routine and tedious checks for bad bearings, metal-to-metal, and so forth.

UAE = United Arab Emirates, Middle East, where the temps right now are lows in the 60's and highs in the 80's. Gonna snow here tomorrow <g>.

Ben Minor

[Degzie]

Well I think we have a result.........Fantastic.

I would first of all congratulate David as he was correct in saying the rx was going in to failsafe, Thank you David & many many thanks to everybody else who contributed.

It was Davids point & a note raised by none other than Ron Lund of ricks helis, that helped me track it down, well I think so 3 good fiights & no lockouts or sudden uncommanded movements.

It goes like this..........The GY611 gyro uses a very fast servo that subsequenly uses alot of power during flight, it was this large power consumption that was causing the problem & had routed the antenna wire a bit too close to the servo harness & I think this was causing a problem.

I will be flying some more on Saturday & I will let you know what happens.

[DavidH]

Degzie,
Glad you found your problem. I see this problem way too often. Pilots will be using a governor and they set failsafe on the throttle to go to idle or engine off. But they Do Not set the failsafe on the governor to cut off when failsafe is activated. Governors are designed to keep the motor at the set rpms until something tells it to cut off. So just setting the throttle channel to go to idle does not tell the governor to turn off also. I learned this lesson when the Futaba GV1 first came on the market about 10 years ago. You have to set the channel that the governor is being controlled from to Failsafe to the OFF position also.

Again glad you found your problem.

David

[Degzie]

Well three months of trouble free flying without any problems and then..............Saturday started flight in normal mode & switched to idle up 1800RPM, did some flips a few tic-tocs then just 6 inches from the deck rightside up in the hover & the glitch returned...........the heli went into the ground skids first, bang..! then recovered back to the hover, then bang again into the ground & recovered then again hard into the ground bang this time the blades failed severing the boom the tail gearbox departed with the horizontal fin, the drive shaft shot out like an arrow & I ficked it into throttle hold, the engine went to idle, this whole incident was over in about .3 of a second, such a large amount of energy was being released the debris covered several meters of the flying feild.
Nobody was injured & now the investigation begins..I will post the photo, If anybody is interested. :(

[DavidH]

If you have the receiver set to go to Failsafe. Throttle to idle and governor to off position. Then this should have happened. If it is not going into failsafe. Then I would say your problem is beyond the receiver. It could be wire chafed or something loose in the receiver.

If it was an RF interference problemn. Then the failsafe should have activated. At least with what you have described it should have.

David

[tnreefguy]

Sorry about your loss. I almost lost my extreme to the same problem. I was getting a lockout from a servo wire rubbing against my clutch bell. Hey Beast Dubai is a city in the small country of the United Arab Emarents. It is on the boarder with Saudi Arabia.