Test flying – Part II

Having left it for a few hours and thought about things .. one thing that came to mind on the cooking was the only major thing I changed on the engine following the ‘downing’

That was a brand new oil cooler matrix ..the original being the only part of the aircraft to take the brunt of the field landing !

This left the old matrix somewhat mashed …i removed it as it was leaking oil in the field on recovery.

What I didn’t do .. was take a photo’ before I removed the old unit and the pipes fitting could easily have interchanged

So, Plan A, is to switch the pipes out of the TOCA, the theory being .. if I had the pipes the wrong way the oil would have to be pushed ‘UP’ from the bottom of the oil matrix vs a gravity style ‘in the top’ method of circulation.

Pipes have been switched, so awaiting good wind direction and strength for a retest

Part II – investigation continues …

So, I thought if the TOCA was causing some sort of problem, ie the thermostat was perhaps causing an issue, I would remove it .. like you do with a car .. and the oul just flows .. uninhibited … right?

Anyway, removed it, its under a little square plate and easy to remove. Test flight number 4 (without the thermostat in place) and 3 minutes into the flight the oil temp started to climb past 80

Pulling around, throttling right back and brought her in on tickover.

On checking with the Jabiru guru Kevin H… it turns out if you remove the thermostat it CLOSES the feed .. completely!

So although this wasn’t what was required it PROVED what was wrong !

I suspect the thermostat valve is STUCK and needs freeing … then putting it back in for another check