Well, there's more to this than I first thought.

Where I thought I had found the issue, as Gaspar suggested, I installed a replacement Air Trap and performed a ground run. Yet again, I observed the rpm drop after initially reaching 130,000. After confirming that this was repeatable, I removed the air trap, and ran my overflow tank directly to the pump using 6mm fuel line all the way, for minimal flow resistance.

After holding 130,000rpm for approximately 10seconds, I again observed the rpm decay to around 126,000. I confirmed that this effect was totally repeatable.

I did observe that whilst running at 130,000rpm, the GSU would show ‘MAX’, but as soon as the rpm started to drop, this changed to ‘Running’. Pw stayed at approximately 1300 throughout at full throttle, both at 130,000 and 126,000rpm.



Even though the logs show 100% throttle, I performed a radio calibration, but it had no effect on the rpm drop after approximately 10seconds.

It is though the FADEC is automatically throttling back uncommanded,

I have sent the Jeti TM data and the FADEC download data to Gaspar for further advice. I am out of ideas.


Paul