Rise and fall of my 40% Yak54

[Neogenesis]

	Quote: Originally Posted by warren cross
	Many thnaks to all who posted condolances,and helpful hints. Sweetpea may be on to someting tho,PCM lock out is the best theirory yet. I dont belive I had any structure failure,rudder failure,as nothing was anwsering the xmitter, the batteries were checked when I got home,all came in at 8+volts with 8 ball checker,at 1 1/2 amp load. Sooooo it kinda looks like a lockout of some sort. Yes I was using 1 rx,a JR2000 select a channel .Iwas running a smartfly turbo reg,and smartfly pro power expander set at 5.8v. I have a new Yak54 on order and will get it late Jan. Will keep all u nice guys informed on progress.

Just another thought. Have you checked voltage post the Turbo Reg? When I initally looked into this system that was featured as fully redundant....there is still one MAJOR point of failure. Both regulators on that system run though a single external voltage controller. That is ultimately the reason why I returned it and went with another system. I've never pumped over 8 volts to a reciever....I don't know how it would act.

It's just another thought.


Neo

[martin18152]

I had a plane go into PCM lock out at the field, unfortunately the throttle failsafe was set above idle, and the plane would not stop, so I had to push it over into the ground, brought it back to the pits, and checked it, and everything was fine, I don’t fly things until I identify the problem, so I took it back to the shop, and started moving the surfaces, after about 1 min, the rudder went to the left, and locked, you couldn’t move with your hand, then the ailerons dropped in another few seconds latter, then the rudder came lose. I let everything sit for about 30 seconds on power, and all the surfaces came back up and work for about a min, then everything did the same failure. The problem was an overheated regulator. When power drops to the transmitter, strange things happen, Fail safe may work, or not up to the point all power is lost. The turbo regulator has a fan that cools the heat sink, it is possible the FOD may have got into the fan and jammed it, therefore allowing the regulator to overheat during flight loads, then after the wreck, the FOD disloged, or the regulator cooled down, and everything seemed fine. Check the fan, it may have failed, and the regulator may not have overheated until you stressed it during flight, they don’t put those fans on the regulator for, nothing. I acctualy had a lose wire hitting my fan, so I secured it, and when I start up the plane, I always check the to see if the fan is running. Note: the regulator that failed was not a turbo regulator, it was on a 33% that I bought, and the guy had the whole system on one regulator and two batteries. Since then, I have replace the single regulator with two FROMCO failsafe regulator and switches.

[warren cross]

Hi Martin,your senirio might have happened,cant say for sure tho, the turbo reg and powerexpander is boxed up and ready to go back to Smartfly. I talked to Robert at the AMA show on SAT and he said to send them in. I hope he finds something out, I will forever be cautious when flying wondering if it will happen again. Will keep all posted if and when I find someting that went wrong.

[sweetpea]

Did you get your new one yet?

[Rolling Thunder]

I had a JR PCM receiver shutdown in air. It never went to failsafe. I went to the wreckage and cycled the switch and it came back. I had it happen on the bench so I switched battery, switch and regulator. Turned out to be the Rx.

I had the engine set to failsafe off and I tested it. The plane went down at half throttle.

[RollingHarrier]

Something similar happened the TheTank last year when he was flying CBK07's Yak. The Crystal fell out of the receiver.
I think Craig tapes his in now.

[matus777]

Warren, have you ruled out a "parking lot" crash? With all the new syn. tx & rx modules showing up (especially with newbys) we have found guys dialing in the wrong numbers (not easy to see). We are now asking guys to verify with another (credible) flyer the newly dialed freq prior to tx operations....hope you resolve the issue!