Moe142

My Feedback: (7)

Today at WDA I had 3 flame outs on my boomerang intro. And the fine piloting skills of Mr Carlos got it back down 3 times in one peice. It has a PST J600R with 74 starts. Mr Carlos is my trainer. So, Initiated the start sequence, the turbine came up to idel speed. Held the jet went to full throttle and all was fine. Taxied out and centered the steering. All is ok for take off idled up and took off in about 200 or so feet and about 5 feet in the air, flame out. This happend 3 times. But the 3rd time is went up to about 20-25 feet and flamed out. Got it back to the pit area, fueld back up, and just tested the turbine at full throttle for about 4 minutes while holding the nose of the plane up and no flame out. But when I went back to idle the turbine kind of sounded like I maby heard bearings?? I am going to post a video of the turbine running. So Kelly from PST North America can hear it. Confused...
Thanks guys, Mr. Moe..

Wayne22

My Feedback: (2)

I had something similar that turned out to be an intermittent receiver switch. It would go off momentarily and the ecu would see no rx signal and shut the engine down...it took a long time to track that one down..
Also a buddy had a servo extension between the receiver and the ECU and it turned out to be a bad one right out of the package....

Sometimes the fault is elsewhere, and the turbine is doing exactly what it supposed to -- shut down when it loses the Rx signal......

BirdofpraY

My Feedback: (31)

How do you have your UAT tank mounted and do you have a picture of your installation?

Kelly W

My Feedback: (2)

Hey Moe,

Hard to say what the bearings sound is, but its probably unrelated to the flame out. I've had a variety of engine over the years (multiple brands and home jobs...) that occasionally sound a bit different between runs. it could be a chunk of soot in a bearing, slightly more / less lubrication than normal... Hard to say, but hopefully its nothing to worry about and it'll go away with another run sequence.

Anyway, on to the more important topic of flame outs...
Did you check the shut down info after each flame out? If so, what did the RPM and EGT readings state, and what asterisk position was being shown? See page 18 for the screen layout and page 19 'After Shutdown' for more info on doing the self diagnosis ([link=http://www.pstjets.com/download/J600R_V1_6_2007_Public.zip]link to PDF file[/link]) If the RPM level was abnormally high, it may have required a high RPM calibration (recommended at the beginning of each day). If the RPM looks abnormally high to the ECU, it will assume a problem and shut down, not typically showing up on the ground due to the lack of forced air into the turbine...

My last question is probably unrelated, but is this the older Boomer without the additional air intakes, or a newer one?

Thanks,
Kelly

PS: If I'm late replying I apologize ahead of time. I'm in the middle of studying for a certification exam next month, and I just got myself a little baby girl a few weeks ago. Don't get on here much but I do try to check my email frequently. It can be found on the PSTNA support page.

Woketman

My Feedback: (6)

Air WILL leak into the system, on the suction side of the fuel pump, if you have too aggressive a bend near a Festo fitting. Ask me how I know! These Festos were orginally imtended for positive pressure (higher press on the inside) applications. A tight radius bend too close to a Festo can result in an intermittent stream of bubbles.

Does the turbine just suddenly quit while at full throttle? Or does it seem to die-off in RPM, then quit? Is there a puff of white smoke immediately following the shut-down?

LGM Graphix

My Feedback: (22)

I had a similar situation with my 1300R during the first couple flights on my kingcat, it was a faulty EGT probe, we discovered that when we jiggled it, you'll get a reading on the start box of 979 degrees. When we would start up all would be good, but in the air, after some bouncing around it would flame out, we could replicate this on the ground by jiggling the probe. The great customer service of PSTNA had a new probe in my hands in a couple minutes and all the problems went away.
Anyway, don't know if the 979 degrees reading is the same on the 600R, but that's what happened with my 1300

Moe142

My Feedback: (7)

thanks guys! Wow!. Kelly I just had a baby three weeks ago too! :-) Anyways I will check everything over today and let you all know. I will also post a vid and pics..
THANKS!!

Koenieboy

I've also had flame-outs on my trefz turbine. The cause was a bad RX-battery. First I thought it had to do with my fuellines or something. But on the ground when testing the turbine I went playing with sticks. When the servo's were moving the display of the ECU went out and also the turbine.

I remember the turbine to flame-out when I came out of a dive (when the servo's use more power than normal) and in your case when taking off.

I was just using one 5-cells NiMH battery. One cell was dead.

Kelly W

My Feedback: (2)

Jeremy, the 979 error is the same for any turbine running the TEMS ECU, or a GB Hobby version for home built turbines. Thermocouples typically fail in 1 of 2 ways... They either break the circuit all together, or there insulation between the dissimilar metal leads in the housing breaks down such that the leads ground themselves to the probe's body.

The broken circuit ALWAYS shows up as a 979 or 980 C EGT reading. The reason for this is that a thermocouple works by producing a minuscule voltage based on temperature. This voltage is heavily amplified, then converted to a digital quantity for the CPU to process. When the probe is removed or the probe breaks the circuit, the amplifier saturated to the top end of the spectrum essentially. Thankfully, it'll always shut down the turbine safely. This very rarely happens in flight.

The grounded probe problem is a little more difficult to diagnose, unless you know what to look for. Upon switching on the ECU everything will look A-OK, but as soon as you initiate the start sequence, the EGT will immediately spike by 100C or so... What's happening here is that there's a ground loop going through either the starter motor, glow circuit, (or both) through the improperly grounded EGT probe, then playing havoc with the ECU's ability to measure EGT. The easiest way to diagnose this is if the turbine won't do the usual 2K- 6K RPM pulsing, as apposed to one drawn out starter impulse in this case, and the gas solenoid will not activate (look for the red light on the valve body) This has never happened in flight (to my knowledge) since the turbine is not capable of starting in the 1st place...

We had a few of those probes in a batch go south on us way prematurely, so the vendor was proactively changed a few months ago. The clear majority of in flight errors attributed to EGT probes is simply a probe coming loose and losing its calibration of inserted depth into the exhaust flow. If the probe wiggles its way out, such that it reads 249C or less, it'll shut down and indicate that as the reason in the last run statistics. Anyway, I know I'm way overkill on the explanation above, but its always worth while teaching users how to better diagnose problems...

Hope some of this helps...
Kelly

JET FX

Hi Moe, just sent you a PM re J600 flame outs...