jetnuno

Hi

I have reached almost 26 hours running time in my P160SE without any maintenance

Even the starter o-ring is the original one. Plus, never had a flameout

And now, what? Send it for bearing replacement? Never got clear if JC recomends 25 or 50h. I guess maintenance intervals have changed to 25h, to help business, or is this unfair?

The turbine is running fine and have always flown in paved concrete fields.

Regards

nuno

Jeffpro

My Feedback: (1)

I know folks who have flown a turbine 60, 70, or 80 hours or more without sending it back. But I'd be afraid to do that. You never know what's going on inside with the combustion chamber, the bearings, the injector needles, etc. For peace of mind, I'd send it in for a checkout. Others may disagree. I believe JetCat recommends 25-hour service intervals.

KC36330

I've got a P70 with over 40 hours and it's never been in for service. i fly only off clean concrete and the turbine shows no signs of needing service. it's well out of warranty so there really isn't any logical reason to send it in until it needs it.

Wayne22

My Feedback: (2)

unless you bought the extended waranty....keep running it until you hear a noise from the bearings......could be a buzzing or a siren - like noise or something in between......the engines do talk to you....J C in europe has (or had) a 50 hour service interval....
If you need peace of mind, by all means send it in......

Carsten Groen

This has been up a number of times...
The explanation I got from Max Reinhart at JetCat Germany:
The 50 hours is if the engine is running in a "clean" environment (university/test fixture etc), the 25 hours are for "normal use" ie in a model jetplane (because of sand/grass and whatever they "eat" in that environment)
So I would change them, correct you might hear "something" before they give up, but what if not ? Are you willing to bet the "life" of your plane and engine if you do not hear this ?

corndog2

You will get bothm sides of the arguement here but I would leave it till you hear somthing. If it aint broke dont fix it

Not sure about Jetcats but the other thing to remember is that with many turbines the timer keeps running even after the turbine has shutdown until you switch of the receiver in many cases so the time on the ECU is rather false

Dave Wilshere

Carsten is correct, JetCat released the two periods because of the number of "lab type" running, I've sold turbines to all sorts of weird people (F1 ) for many different uses. It should be a clear time and in reality its 25 hours for our use. I also have run way past 25 hours (I had a P-120 with 42 hours when I finally sent it in) Bearings are only one thing, fuel needles, combustion chamber, even build up around the NGV.
I listen for changes, at this time Service turnaround in Europe is still slow due to the level of work, I suggest you call JC direct and ask them for advice

Dave

Justflying1

I have made some inquires my self about this.

Harley Condra

My Feedback: (4)

Nobody has said this yet, so here goes.
Keep an eye and ear on the spool down time after shutdown. It is easy to measure the time it takes to stop after shutdown on your wristwatch....The spool down time will decrease as the bearings wear increases. When the bearings start to make a louder or different sound, or the spool down time decreases, stop running it and send it in for inspection and bearing change.
Not mandatory, but it is a good idea to send the fuel pump and ECU to the shop along with the engine core.
Catastrophic failure of a bearing can cause major damage to the engine and your wallet.

tulz161

Why does the cooling down time decrease?

dsr71

My Feedback: (171)

has to do with the bearings draging as they get older so the turbine will not free spool as long at shut down ,has anyone checked to see if the run time starts when the receiver is powered up ?

KC36330

JetCats only logs actual run time.

Eddie P

My Feedback: (4)

No, not COOL DOWN time, but SPOOL DOWN TIME. What you see in engines with bearings that aren't kosher is higher drag on the shaft and bearing noise from the bearings themselves. Before the bearings fail, this is a late sign of impending failure... and you can often "hear" the bearings with a different sound when the engine is spooling down along with, if you are very observant, a more rapid than normal deceleration as soon as the fuel cuts off and the fire goes out. This isn't a scientific metric but it's a good wide perspective observation. Even full size engines require rather agricultural maintenance observations at times as a part of official maintenance. One engine I've operated in real life (a Rolls Royce model) required the maintenance guy to do a specific "smell test" of the engine oil sump a certain amount of time after shut down during every transit stop to make sure the fuel oil heat exchanger was not leaking fuel into the engine oil supply. So if a 747-400 needs a "smell check" after every flight then it's reasonable that our little engines get a "listen check" on spool down when you shut down.

FlyinTiger

My Feedback: (45)

I'm still in the beginning stages of learning about turbine maintenance on RC models, but another measure of required service - this time for the fuel filter - is when the fuel pump current climbs for a given RPM. Correct me if I'm wrong, but checking the ECU for max pump current after a run is the way to get this reading.

KC36330

if you're filtering your fuel like you should (before filling your field jug, between jug and plane, UAT) then your filters shouldn't ever get clogged enough to cause a spike in max pump, it will show you if you're developing a restriction in the fuel delivery system but 99% of the time it's not the filter.