alasdair

I have been running two of these original Graupner Booster 160 engines for a while. Both are still low-hours but have been running well.

Then last Saturday a small group of us were invited to fly atthe RAF Leuchars Airshow as a warm up act while the public were arriving in the morning.
I took my CARF Lightning and Eurosport (F20 Tigershark and Eurofighter, to Joe Public) each with a Booster 160 to fly in front of thousands of people.

The Booster in the Eurosport started perfectly as usual, but when I throttled up to taxi out it mad an unusual 'faffing' sound and flamed out with white smoke.
I restarted it, and ran it up to full power quite normally, then stopped and refuelled.
next time I started it up to fly it did it again. As soon as I opened up to taxi power it went "fa fa fa fa fa....." and flamed out, white smoke again.

I shut down, started the Booster in the Lightning, flew quite normally for 5 minutes and landed.
While taxying in, as I applied a little extra power it went "fa-fa-fa-fa...." then blew four feet of flames out of the jet pipe. I shut it down immediately. The inside of the jet pipe is a bit sooty but undamaged.
The cool down cycle was normal each time.

The weather was cool and damp (Scottish summer).

Any ideas why two normally reliable engines should behave like this? Are they shy when performing in public, or alergic to moisture???

Are there adjustments I can make?

Meesh

My Feedback: (135)

When it's humid there is less oxygen in the air to support combustion. You were probably putting more fuel in than the engine could burn. If you have access to Acceleration parameters via the GSU then you should try lowering those numbers when attempting to fly in those conditions.

Bob

George

My Feedback: (57)

Those engines are susceptible to humidity. One day it will run perfect and the next it will not accelerate without VERY slowly advancing the throttle. The only cure I had was not to fly in those conditions.[] And no! changing the accel to low/high does not help.

basimpsn

My Feedback: (5)

That could be it .

powerjets

My Feedback: (1)

For sure...thats how it works ![:@]

LGM Graphix

My Feedback: (22)

My booster 160 didn't care about humidity so much but would do the same thing at very high density altitude. As long as I pushed the throttle stick smooth and slowly it was a non issue. Once flying it was fine. The other booster at that one meet was the same. At that same meet my old gen 1 pegasus would hang at mid throttle if I accelerated to fast on thottle. A few jetcats and all of the jet central engines there did the same thing. Slowing down the spool time on them all seemed to cure the issue.

hmjets

Hi
verify if your ECU batery is Ok...

Steve Moore

Hello,

I had a temp probe fail on my booster 160, I sent it to Evo Jet for repair, whilst chatting to them they said that my engine had the old type combustion chamber and since that was made they have designed a new one. Now, they said my combustion chamber did not need replacing but their new version had been designed for customers living in areas of out of the ordinary atmospheric conditions. I am not sure of the cost involved but maybe it is worth talking to Evo Jet to see if this newer chamber will solve your problem?

But I know what you mean, I always S**T myself in front of thousands of people why not have your engine do the same??



Is this the first time you have had this problem?


What fuel/oil are you running?


The chances of having 2 faulty pumps at the same time is strange, unless they have been stored unused for a length of time and become corroded (had that on my P200 recently, thanks to Dave Wilshere at Motors and Rotors it was rectified).


Good Luck

alasdair

Thanks everyone,
I checked the batteries, and they are fine.
It was a new batch of fuel, but I've just run my Wren on it and it was fine.

The models had both been run recently, the Lightning at Woodvale and the Eurosport at Elvington, and then put away for the Leuchars show.

The Booster in the Eurosport did flame out before takeoff once at Elvington, but I put it down to the taxi tank.  At Leuchars I didn't connect the taxi tank the second time, and it happened anyway.  The Lightning had never done it before.

I can't find any adjustments to the acceleration delay, or any way of softening the throttle response, in the instructions.   Any ideas?

George

My Feedback: (57)

If you have it, it should be in the "RC Settings" section of the Menu and is called;

5A:THROTTL-TYPE
Selecting the throttle transferfunction for the engine speed (throttlecurve).

SOFT = The Throttle works rpm-linear, e.g. softer in the lower rpm range.
Better for smaller and lighter airplanes.

HARD = The Throttle works thrust-linear, e.g. quicker in the lower rpm range.
Better for bigger and heavy airplanes.

alasdair

George,
Thanks, I found it. I'll give it a try.

Malcolm H

Alasdair I don't think that adjustment affects the acceleration delay in any way.

It is a throttle stick to power output curve adjustment. Basically in "soft" the stick position to engine speed is linear (and the thrust exponential) and in "hard" the ECU applies a logarithmic function to the stick position signal to give a more linear stick to thrust ratio.

When are we going flying again?

Malcolm