InboundLZ

My Feedback: (10)

Ahhh, the learning process...

Some of you more experienced jet jocks will get a laugh out of this little exercise in what not to do....

So, on my very first flight I landed and the engine shut down on roll out (Behotec J66/ProJet ECU V5.2). So , in an attempt to determine the reason for shut down I connected the ground service unit (GSU) to read the shutdown cause but I could not find the *Last Shut Down* menu and was unable to determine the reason for shut down. So I did what anyone would do, I ran the engine again...no problems...so I flew again...no problems and was able to land and taxi back without any issue. I contacted the dealer that I bought the engine from and he advised me on how to access the code for the last shut down.

Now, I figured that the shut down was do to loss of signal/lockout because the antenna is on the bottom of the airframe and the jet was 400 feet down the runway with the antenna pointing directly at me, but I could not prove it. So, now that I knew how to determine reason for last shut down I figured I would run a little experiment. The plan was to start the engine, the turn off the transmitter to induce a "lock out" scenario. The engine would shut down and I could, now that I knew how, access the last shut down reason on the GSU. All good right? Wrong!

So, I go to start the engine, but she no start....I get propane light off, but she does not accelerate and run on fuel. It auto aborts the start.... So I check everything and try again...no joy...same thing, propane pop but no start. Now keep in mind that I am using an external propane bottle but I am using the on-board propane valve. Now, normally I close the regulator on the bottle after every start....(can you see where this is going?) but not this time. So, after looking everything over again, I make yet another attempt to start. This time when the propane lights off and so does most of the airframe...yep I have a fire, a propane fire....as I have my Halon bottle handy it is out in a few seconds with no damage except for my triple heart rate.

OK, so what gives? Well, I can see that no fuel is flowing to the engine so I decide to run a pump test. I disconnect the fuel supply line to the engine and run the test...everything works normal...what the heck? So I reconnect everything and try to start again. Presto! It runs...ok...now back to the experiment...I shut down the TX and two seconds later the ECU shuts down the engine....perfect!

So, using my new enlightened understanding of the GSU, I search for the last shutdown reason but all I can find is "userbreak"...more on that later...

Well, what to do? Well run the engine again of course.... Another start attempt, and another failure....***???? OK, I figure I have an empty propane bottle so i send my son for a new fresh one....Attempt again, with the new bottle, and she lights off....REALLY LIGHTS OFF....yep...nice blue flames out the tail pipe that promptly remove the covering on the horizontal stab (baby boomer)...can you say to much propane???? So, I abort the start, clam my kid down as he has the Halon bottle and is ready to use it! Figuring that I understand what I did wrong I make another attempt. She starts, finally! So I run my test again and shutting off the TX results in the engine shutdown. I check the GSU for reason and all I find is "userbreak"...ARRRRRRRRRRRRRRRRGGGGGGGGGGGGGGGG!!!!!

I decide to bag it. I had 4 missed starts, two fires, and damaged covering so I figure as I have had a banner night it was time to hang it up! The lack of intel from the GSU was really bugging me. Why did it not indicate the loss of signal? All it says is "userbreak"....WAIT....and then it hit me! The ProJet ECU does not automatically shutdown the engine if it sees a period of time with no signal like a Jet Cat ECU will. Therefore I had to set up failsafe in the RX to move the trim and the throttle to the lowest position...the EXACT SAME THING I have to do when shutting down normally. A normal shutdown results in a "userbreak" indication, so guess what....a lock-out condition will also result in a "userbreak" command to the ECU, therefore my last shut down reason will also result in a "userbreak" indication!

So, in the end, I learned some good lessons the hard way. No real harm done, stab is recovered and everything is as it should be....

I am rapidly gaining experience! <G>

seanreit

My Feedback: (60)

If I had a dollar for every time I set my airframes on fire, I'd be in a more expensive hobby than I am.

Keep trucking, you'll figure it all out!