smitty1001

My Feedback: (29)

Eric,

Sorry to bother you on the holiday. I had a "crispy" mother's day. I was going for my 6th flight of the day - everything normal - turbine transitioned from propane to kero and was ramping thru the 20k's when suddenly it came to a quick halt - I thought it had seized it stopped so fast - huge orange flames that seinged the monokote off of the boomer stab. I of course shut-off the manual valve as soon as possible but the flame kept burning - the turbine wouldn't enter cooldown mode (trim to idle at this point and thumbing frantically to the "test starter" option) - at this point the temp was at 450 and the rotor was at a dead stop - not good! Smoke was coming out of the front (compressor) and orange flames out of the tailcone. The GSU said "Bad Start".....!!! NO $h!& ECU!!! I would go as far as to say "Exteremly Bad Start"

Anyways.....I cycled the ECU and then it would let me thumb to the test starter menu and I ran the starter which blew the flame out with a spectacular "poof" which was about a 1 foot diameter ball of fire. As I said earlier, I thought it had seized as the other Falcons that we hear about but it spun freely with the starter motor so after it cooled down, I slipped the FOD screen forward enough and turned it with my finger and it felt normal. I tipped the plane on its nose so I could visually inspect the turbine wheel and all appeared normal. After looking over the menus in the ECU I decided to give it another go with the fire extinguisher in hand, the other on the valve.....I also had a leaf blower handy......

Same thing as before = everything normal - turbine transitioned from propane to kero and was ramping thru the 20k's when suddenly it came to a quick halt - I thought it had seized it stopped so fast - except this time I was ready. Hit it with the leaf blower - ran the "test starter" function and it was a little less fiery. Nevertheless, it is in the box with the ECU and fuel pump.

A couple things about this motor: almost 20hrs runtime, (it went in after 10 because of the "shorting" issue and the ECU timer was reset so it reads only about 600 minutes. This turbine has never been run at full throttle (unless at the factory) because I have it dialed down to 118k.

While I am glad this happened on the ground and not in the air as with others, I really would like to know the cause of this event in addition to it being repaired. I know your service will be prompt and great as always but so far things have just been fixed or replaced but not any answers as to what caused them to begin with or how they were rectified. I have so much trust in my Artes turbines that I have gotten really relaxed during the starts - it just always works - so you can see what a shock it was today when she was in flames and halted so quickly. I feel like I was just dumped by my high school girlfriend!

Some of the prop guys at the field were like "that's cool." I said, "not cool, not cool at all, something very bad just happened!"

Anyways.................it is on the way to you - if you run it just be ready for the 24k-ish mark, you'll be pretty busy for a minute after that!

Smitty

smitty1001

My Feedback: (29)

A side note:

I sure wish that you could get to the starter motor function easier in an event like this - when there are flames and/or high temps with no RPM and it takes you forever to get to the menu it really sucks. Could Gaspar program the ECU to power the starter if both buttons were held down or something like that?

joeflyer

My Feedback: (48)

Smitty,

All you have to do is set the idle trim to low and the throttle to full. This will engage the starter motor as long as the temp. is above 100C. You can then cycle the starter motor if you wish by moving the throttle lever up and down.

Joe

seanreit

My Feedback: (60)

Joe/ Eric,

I have observed this situation before, and have always wondered why in this particular emergency situation the starter motor doesn't engage cooling the turbine down.

The only conclusion I have ever been able to fathom is that the software has a piece of ladder logic that says if a parameter is out of normal, and manual shutdown from the transmitter has been commanded, everything goes to "off" position.

I can't think of any software scenario where it would be a bad idea to run the starter motor during a software commanded shutdown coinciding with a transmitter commanded shutdown.

I always have a blower with me. I will say one thing for sure, I have observed this sequence of events far more times with this brand of turbines than other brands. I was always told it was because of the tolerances between the turbine wheel and the Exhaust Gas Vane.

The next part I made up, but don't know it to be true, so if anyone knows for sure, I'd sure like to be corrected.

My theory has always been that Jetcat is making their turbine wheels smaller, or the egv clearance larger so that it is less likely to get a rub. This would explain how essentially the same turbine components would give jetcat less real thrust than they always advertise, and then Jet Central having more thrust.

As long as I have been in the game, I am almost always over thrust for a particular installation.

If in fact, jetcat is detuning their engines for more "reliability" (whatever that means in this game, cause I'm really not sure, all manufacturers suffer from one problem or another), has there been any discussions at any level if it would hurt market share to try to attain a better reliability record? And is what I'm mentioning one way to achieve that?

Sometimes I fire up my Engines and wonder if I'm crap shooting. Specifically because I bought into this program swayed away from four jetcat engines because of the lifetime warranty. It's great that Jet Central has fixed engines issues when I've had them, but in the mean time, I'm out about $2,000.00 in airframes, not to mention the time it took to build them. All the time wondering if the additional thrust and "protection" (and by protection I mean knowing that Eric/ Phillipe and team will resolve engine issues) was really worth making the change.

If none of this makes sense, please tell me that as well. I haven't been drinking tonight but do sometimes say things in such a way that could be misinterpreted, or misunderstood.

Smitty, I believe you had a classic rub of the turbine wheel to the egv. Sometimes a little surgery with an exacto knife will clear out the rub, next time we're together I'll show you what I'm talking about.

All the best,

Sean

Edit: Smitty, if it was a rub, the reason it would spin later was because of heat expansion. Once it was cooled, there was enough clearance to unlock and spin freely.

Also, to be perfectly fair, the first time I ever saw this happen was on a P-120 about 6 years ago. It was sent back to Wilcox (I think this was before Redman was in the picture) and I'm not sure what he did to fix it other than maybe he dremeled or picked off where it rubbed).

smitty1001

My Feedback: (29)

Joe,

I did not know that, thank you very much!

Sean,

All that makes sense...........I felt like it was a "rub" when I saw that I still had all blades and it would turn freely. The heat expansion explanation is right on - I had the same thing with my first turbine (P-80) and second (P-70). Redman told me when he fixed the '80 that there can be a build up of residual "gunk" (for a lack of a better word) at the NGV/wheel area that, as temps increase, can cause a rub. He ended up machining-in loser tolerances to keep it from happening on the '80 but did say that an exacto or dental hook could be used if it was minor and you knew what you were doing. When the P-70 started doing it (post Redman) it went in and was gone for 6 weeks or more and had a bearing change. Like you, I have been happy with my "switch," but wonder if it all ends up being a wash seeing how they all basically have problems............luckily, none of my problems have happened in the air, and so the Jet Central route has been much more flying for the dollar as compared to Jet Cat for me personally. I had to send my Jet Cats in, on average, once every 20 or 30 flights @ several hundred dollars and a long wait each time. My Falcon has been in once for that shorting issue with the EGT & RPM sensor (after about 10 hours of run time) and this will be the second time - only costing me shipping and basically back within the stated timeframe. No problems so far with the superbee other than the long accel and decel time which I believe has been improved with simple adjustments. It has about 8 hours on it so far.

I was really excited about getting a Rhino this summer and probably still will but, I feel like I just took a few steps back today with my confidence in the reliabilty.............[&o]

Gaspar

No need to think too much, exactly in this one.

It seems that it is a rub, the turbine wheel touch the EGV due at uneven heating up, the 99% of the cases caused by excess of propane during startup.

In this scenario, if the starter is commanded with more power, the only result will be a burned out starter and posibly the ecu. When the engine is "seized" there is nothing that the ecu can do to turn the rotor.

Anyway, as joeflyer coments, you can command the starter to run from the TX for cases like this one. Just take care, if the engine is seized you can burn the starter motor or the ecu if command full starter enough time.

Gaspar

seanreit

My Feedback: (60)

Gaspar, thank you for the comments, the voice of experience sure over rides the voice wonderment.

Any chance it would make sense to put a short blow fuse in line for this condition? Or is it just our duty to keep a blower near by?

Also, I would agree based on my conversation with phillipe that this is caused by too much propane, but my question is, how much more would it cost, or why wouldn't Jet Central, Merlin, et all, install at least a two or three tube propane distribution system rather than the one? Wouldn't this help the situation? Or is this yet another compromise in aviation, IE you get this, but give up something else.

Thanks,

Sean

Gaspar

No, it don't make any sense. You put too much propane, the egv distort and rub to the wheel, and the ecu push the starter at full steam to keep the rotor turning without success... the fuse blows. And now what? You still need to use the external blower or fire extinguisher... I don't see the point. If the starter just stops, you, the operator, have the chance to manually switch the starter on trough the transmitter and see if the rotor turn (likelly it will do in few seconds as soon as the heat spread evenly trough the EGV). It makes much more sense to give to the operator as many chances to correct the problem than to blown a fuse that don't will give you any other solution.


The problem is basically of too fast heath-up, not distribution. I cannot speak for other companies besides JetsMunt, but the main problem that we have is that worldwide you find very different gas pressures. In hot climates you find butane/propane mix with a propane content as low as 20%, that give a pressure of around 15-20 psi, and in other sides what you find at the shop are different blends, up to 100% propane that give a pressure of over 100 psi. So a engine "tuned" for butane/propane mix will likely overheat with 100% propane.


Gaspar

seanreit

My Feedback: (60)

Ahhhhhhhhhhh. This would explain why I would see the rub more often across engines in Texas than elsewhere. There are a lot of 100% propane starters here. I never considered the mix vs the 100% in regards to start temperatures. That would make a big difference.


Thank you for saying that, it's soo obvious, but in all my years in this, it has never come up in conversation.

BluFox

My Feedback: (10)

Smitty:

I do apologize for my not being able to take your call yesterday. When you called, we were right in the middle of each son paying verbal tribute to their mother and vice versa.

The issue you describe is or was infact the NGV distoring and rubbing the turbine wheel. The ECU senses the turbine slowing and commands the fuel pump to put more fuel as the temps are not at idle temperature. This in all probability caused the nozzle fire.

Responders are correct, that is to say Gaspar is correct with his analysis as well as joeflyer with his "trim low - stick high" to run the starter motor. The reason the ECU does not automatically go in to auto cool down under these circumstances is it (ECU) does not know why the sudden stop. If in fact the turbine was seized although temporairily, the starter motor would engage, be unable to turn the turbine and then possibly self destruct. You did everything correct.

I am leaving for Mexico City Wednesday morning at O'Dark Thirty. What I wish to do is overnight you documents completely filled out. All you have to do is pack the turbine, ECU and fuel pump in the case / box it up ans attach the documents when you receive them. Take to the nearest UPS and drop it off.

We will replace the NGV and Turbine wheel, check both bearings and get it back to you next week.

Please call me with your shipping information so that I may get these documents out to you today.

Best regards,
Eric Clapp
Jet Central Micro Turbines
Lifetime Warranty

smitty1001

My Feedback: (29)

Eric,

Wow....................

Here is work:

James Smith
7332 Douglas Lane
North Richland Hills, TX 76180

BluFox

My Feedback: (10)

Jim:

On their way to you tomorrow. I will look for it Friday at the plant or no later than Monday.

Thanks,
Eric

smitty1001

My Feedback: (29)

Thanks Eric - awesome service as usual. How about some pics from the plant?

Gaspar and Joe: I didn't realize I could run the starter like that - that makes perfect sense that it was programmed that way - thank you for that info!

I confess to being a 100% propane starter although I always run through the solenoid, restrictor and use a variable knob. I switched from powermax so I could just use the big green bottle and not deal with the trigger valve and that whole parade everytime....BUT.................................. .......if this causes the "rub," I will never use it again! Are we being advised to go propane/butane mix to avoid this situation?

Thanks everyone,

Smitty

causeitflies

I thought they used propane exclusively at the factory...

seanreit

My Feedback: (60)

They run the engines on propane through the "fuel" line for test runs. However, this scenario, you have an even burn...........

BluFox

My Feedback: (10)

Smitty:

No, continue to use what you have been. You may use the "on Board" tank hand held outside the jet or install as per the manual. Where people get in trouble is the adjustable valve you are using for the propane tank, Just get a torch nozzle, cut of all but about 3 inches then braze in a piece of tubing. Place clear Festo 4mm line (you can see gas moving) and safety tie to secure. When ready, connect to the one way Festo valve, turn upside down and fill. That should do it. Remember, your best start gas and glow plug value are the two lowest numbers which insure successful and consistant starts each and every time. The problem most have is when the turbine is sluggish to start, they think more propane. More propane means more heat. Let the ECU and gas solenoid do their job. Watch temp at preheat. When it reaches 100 degrees, then fuel is introduced to the start process and fuel ramp begines. With the Falcon propane cut off is about 18,000 RPM.

Sean:

Sorry my friend, but you are wrong. Think about your post. If we as you say ran the propane through the fuel line, this means the fuel solenoid must act as the gas solenoid during preheat. Not possible as when the gas solenoid is commanded to shut off, so would the fuel shut off and vice versa. We test every turbine with the exact same set up included in the system. One way valve to white tank, tank to Festo gas valve and gas valve to filter and restrictor then to turbine. Yellow Festo line all the way. Exactly as the system. Total length of our gas system on the test bench is very close to 18 inches of Yellow Festo 4mm line.

Smitty: Yes, will take pictures of our facility and post as soon as I can.

Regards,
Eric Clapp
Jet Central Micro Turbines
Lifetime Warranty

seanreit

My Feedback: (60)

Eric, please check that statement with Phillippe. I got my information from him. He told me in March that that was common practice down there.

As rarely as I speculate about something, I make sure to mention that. Not the case here, if maybe somehow I misunderstood the circumstances with which he was referring, could you find out about that and correct me? I would greatly appreciate it, cause what he told me at the time made a heck of a lot of sense to me. Lightning the burners on propane for a quick check and run of the turbine would be a very efficient fast way from a controlled test stand environment to make sure all is as it should be.

Also, please check your statement "Not possible as when the gas solenoid is commanded to shut off, so would the fuel shut off and vice versa."

A turbine of any brand could in theory be run on 100% propane if the bearings were being properly oiled.

My guess is you and I are on different pages, cause there is no way in my mind I could know something about these engines that you don't.

Have a great trip and tell Philippe Hello from Texas!

causeitflies

Sean,
What I meant is that PowerMax is not readily available in Mexico so they use propane for starting, in regards to Smitty's question about switching to PowerMax. I can see using propane to check the injector needles for even flow when the engine is apart. But using propane instead of kero to actually run the engine wouldn't give a good indication of how it would perform IMO. Plus you have to lube the bearings so why not just run it normally? Seems like extra work to do it both ways.

smitty1001

My Feedback: (29)

Eric,

I finally got the papers late friday (no fault of yours, secretaries didn't get it into my box until then) I dropped it off at UPS on Saturday - please advise when it arrives at the factory. We still want an inside look at the factory! So let's see some pics!

Smitty

smitty1001

My Feedback: (29)

Eric,

Can you or Philipe confirm that you have received the falcon at the factory?

Smitty

BluFox

My Feedback: (10)

Hello Smitty:

Yes, I received it at the factory. Inventoried included items and scheduled for service. Two tech's volunteered for OT as crashes were in abundance this past week.

Your turbine is scheduled to ship no later than Tuesday. I will be informed of any delays and reason if any. I returned to US soil late this afternoon after 12 hours enroute. UGH. . .flew Untied and Ted. . .Yes the spelling is correct. My wife retired from Untied in 03 after 39 years of walking millions of miles serving millions of pax. Still a great airline. We (Jet Central) have many UAL employees as customers.

Enough of the what's and why's. . .will keep you informed.

Best regards,
Eric

smitty1001

My Feedback: (29)

Awesome.......Did you get any pics of the factory? Maybe after you get some rest you can let us see where some of the magic is done!

smitty1001

My Feedback: (29)

Eric,

Did the Falcon ship out today? If not, can I get it shipped to my work address? 7332 Douglas, N. Richland Hills, TX 76180

Smitty

BluFox

My Feedback: (10)

Smitty:

Your address change is noted. Your turbine will be sent to this address.

Best regards,
Eric

BluFox

My Feedback: (10)

Smitty:

Falcon has taken flight. On it's way. . .

James Smith 1Z 022 969 04 4826 8815 JF 100-118 UPS tracking number as you requested


Best regards,
Eric