140RX Blades Rubbing After Service
 

Hi,
I recently had my 140RX serviced with the bearings replaced by Jetcat. After getting the turbine back, I turned the impeller by hand and found that the blades are slightly rubbing. I had advice from Intairco that as long as the engine temperatures were normal when running that it should be ok. I ran the turbine up at home and all temperature and rpm parameters seem to be normal. I have since had 5 flights with no issues, but upon starting I am still getting a noticeable metal on metal rubbing sound. Is this something that will go away or should I send the turbine back to be checked out? I am a bit worried that the fan blades could get out of balance and do some serious damage at full rpm.

Regards
Greg

Hi Greg
No its not normal and I wouldn't run it that state, every time a blade scrapes the turbine ring a number of things are happening inc. vibration, hot spotting, gauling, fatiguing etc. Its a very easy fix so i suggest you get it seen to.

Thanks for the reply. I ended up sending it back as I wasn't comfortable running it in that state.

Regards
Greg

I sent my 120SE to JC Germany and upon return also have same issue. What is their policy on this? I spent $395 plus shipping and am a little confused that this could even happen.

Hi Alan, Jetcat will fix it definately.
The probable reason why it happened is because Jetcat uses very small turbine tip clearances (a good thing for efficiency) BUT.... The alignment of the NGV in the older Jetcat engines is reliant on the strength of the Outer Can. A big enough jolt in transport is enough to slightly alter this alignment. The fix as crued as it sounds is to hit (from the rear going forward) the outer NGV ring at the rub location with an alumium drift just enough to restore the clearance. Other than this a shop capable of restoring the outer cans intended shape with engine dismantled is required.....or a new case.
Its not a big issue, I've done this repair a stack of times, most recently at a jet event where the owner would have been forced to shelve his flying for the weekend.