Meesh

My Feedback: (135)

My flying buddy maidened his Ultra Flash on Saturday with a P120 in it. He did a full run up to full power with the GSU connected and confirmed the max RPM @123K. He also did full range checks with and without the Turbine running.

Take off roll and lift off were picture perfect, he executed a turn to downwind, flew about another 800 feet and the engine just shutoff, no smoke.

Plugging the GSU in after a safe landing, he observed the Hi RPM to be 142,300. Cause for shutdown was Overspeed.

A subsequent run on the ground indicated a solid 123,000.

Is this the RPM sensor acting up or the RCU or a combination of both?

TIA
Bob

KC36330

It's usually a temporary restriction in the fuel system that causes the pump voltage to rise to keep max RPM then the restriction is flushed and RPM surge before the pump voltage can drop. Only way to know for sure was to look at the ECU data before you ran it again.

Meesh

My Feedback: (135)

KC

MAX Pump Voltage was 2.5V. I saw it myself.

KC36330

Without looking at those last few seconds of the run info it's just a guessing game. The above being the most probable.

Meesh

My Feedback: (135)

KC

Wouldn't the MAX pump voltage recorded in the ECU for the run be the Maximum Voltage that was recorded during the run?

Does 2.5V sound high to you?

What you explained to be the cause sounds logical but I don't know that 2.5V isn't normal for a top speed run.

If you say that 1.8V is normal then your assessment would seem to be the reason for the flameout.

We're hoping that it's something as simple as this. He doesn't want to send an engine in at the Beginning of the flying season here in the Northeast.

Thanks for your help.

Bob

KC36330

It varies depending on the particular pump and mainly the fuel system plumbing but 2.5V is typical for a 160 not a 120.

Meesh

My Feedback: (135)

Thanks KC!