Wojtek's 400 was test run 4-5 times today with no problems. I would like to know more of what happened on the last flight. You could PM me or post it. Intial inspection was that the rotating assembly was spinning properly with no noise other than normal. I had Derrik take off the outer housing and do a visual inspection of the turbine wheel/stator wall and look for areas where the wheel would have made contact. The motor was reassembled and ran flawlessly. I do not have a test plane for engines but am interested in a new Boomerang ARF, has anyone seen the price for one?
Rodney Evans~Technicial Specialist AMT-USA
I just got back in now, so here is what happened .... Flying around, and on a slow low pass, at idle, the engine dies ... came around and landed ... When I got to the plane, I tried blowing some more air through it with a blower to cool it down but it did not turn. When it cooled down, I tried turning it by hand, and it was stuck. ... After a few more attempts to turn it, something let loose with a bit of a clang, and it spun freely, this was similar to the 1st time it ever seized up on me, and at that time I was told it was an issue with a preload washer. When spun over by hand now, there was a noticeable clanging coming from it, this was not the typical sound if bearings being loose either, i have over a dozen engines, and I know what good bearings can and should sound like, and this clanking was definitely different. I have 2 people who were out at the field with me that day, and they can attest to this .. one of them being a very experienced and notable jet modeler. To tell you the truth, i thought the bearing cage blew out by the sound of the noise. by the way, i did plug the GSU into the ECU, and the error indicated failure was due to was "low RPM". After I got the engine back from the factory last, it ran just fine 3 times, all during 8+ min flights ... all shutdowns were cooled down with air to below 90c with both a blower and compressed air. On the 4th flight when it quit on me .. and as on the prior seizures , ( one of them was so bad, the turbine shaft would not spin at all .... ) the engine dies at a low throttle setting, after a round 2 - 4 min of flight at varying throttle positions. I'd love to be all excited that it ran fine on the bench, but when will it seize up again ?? 4 flights later ? 10 ? what was the clanking sound ? if its not the bearings, not the preload, not the holes to the wrong spec, not the bearing housings in the tunnel, then what ?? I refuse to be a guinea pig any longer? This engine has caused 4 in flight failures, each almost catastrophic... I can only see 2 ways I'll ever fly a at400 on my king cat again, either on a brand new at400 which is built to new spec, or if the old one comes back with a warranty that is inclusive of covering my KingCat for crash damage in case of subsequent failure, including property damage that may occur due to an engine failure induced crash.. Rodney, of all the guys at AMT, I appreciate your help and support the most. You of all people understand the most as to what I’m dealing with as you have worked on my engine back while AMT was with Jim in WV, and now in OH with the new guys (i guess it was not just an asset purchase was it ... hmmmm ... ) .... By the way, i also got the voicemail tonight that John Ligons left on my phone .. I will call you on Monday John and we can go over this further... anyway, let me know what you guys will do about the engine.
Wojtek