Prop Controller Failure

-

 On our way back from Oshkosh we experienced a prop controller failure. Three blinking red lights, which according to the documentation indicates "Slipring Brush Worn Out". This had to happen at the worst possible time just as we were arriving at Wendover airport (KENV) which is at an altitude of 4200 feet and was reporting 45C. 

I can't remember the exact density altitude, but it was definitely greater than 8000 feet. Luckily we had some intermittent manual control and we were able to get the prop into a position where we could continue to fly, keeping a close eye on the engine RPM, making sure not to overspeed it. 

After refueling we departed using RW08 (10000'), and we were able gain altitude without any trouble. But during the climb out, to add insult to injury, the GTN650 decided to overheat and report a "Cooling Fan Failure". Luckily that cleared up as we got into higher and (slightly) colder air.

Back in KPAO I emailed Airmaster in New Zealand. We got a quick response from their support team and received a trouble shooting guide. Using this guide and continuity tester, we quickly located the problem; one of the brushes had a broken wire. That seems kind of and early failure after only 250 hours.


We got a new set of brushes from Airmaster, which took a week to arrive, and installed them using the instructions they provide. That was quite easy; you basically clean the solder of the original connection, and solder in the new brush, leaving enough room for the spring to extend.




After reinstalling the brush assembly and testing the prop controls, it all appears to be back in good working order. Problem solved.


Comments

  1. AnonymousSeptember 11, 2022 at 12:04 PM

    This (3 flashing reds) also happened to me at 330hrs. I needed to reboot (toggle the prop control switch until it settled), made it to AMO. First they replaced brushes but it didn't solve the problem, so a be unit was installed.

    ReplyDelete

Post a Comment

Popular posts from this blog

Customizations

-
Image
Before we started our build we selected  several custom options for our plane. Strangely enough, there is no list of all possible options. We just had to keep asking to find out (HINT: someone at TAF should make a list). Anyway here are a few options we selected as part of our order:  Split Rear Seat - This will allow for three passengers and luggage. We also plan to make the rear seat removable because we most often fly without any passengers and lots of luggage. Extra Long Seat Rails - My family is really tall, so we asked for extra long seat rails. This will allow them to move the seat back a few extra inches to accommodate for those long legs. Foot Pedals - The standard it comes with really cheap looking rudder bars. It turns out there is a option to get custom aluminum Sling branded pedals. They are on backorder. Besides the options from the factory, now that we are building we have learned about many small modifications that other builders are making. Here are some that we are
Read more

Floor under Back Seat

-
Image
For some strange reason, there is no floor under the back seat. I guess Sling expects the back seat to cover any cold air leaks and stop stuff from falling into the space below. This seems really sub-optimal, dangerous, and needs to be addressed. Without a floor, the seat belt buckles can be pushed through the seat and fall into the space below which houses many important linkages that are needed to fly the plane, so that could be bad. Also there is a huge amount of cold air leaking into the cabin from underneath the seat. To fix this I decided to add aluminum floor panels under the rear seats, to close up the space. They are mounted with rivnuts, covered in carpet, and easily removed for inspection. The final result shown in the first picture.  It is an easy build; you need a rivnut tool, metal scissors , rubber mallet, and a few others. Measuring, fitting, and installing requires various advanced yoga poses, but it is doable. First I made a cardboard template for the two panels, meas
Read more

IPad panel mount

-
Image
A few weeks ago I got the new Apple iPad mini. The smaller form-factor is perfect for the Sling TSi. However, I don’t want it to be floating around on my knee, so I have been looking for a good way to mount it somewhere so that it is hands-free and does not obstruct the view or the instruments. I think I have found a good solution.  I  got a tablet mount on Amazon (link   here ) with a short adjustable arm and   attached the mounting point to the left of the panel (see below). The panel is made of aluminum, covered in leather. I used self tapping screws with plastic washers, but you could use rivnuts. Here it is with the arm attached.   I don’t like the tablet holder that came with it (too bulky), so instead I used another mounting point (Amazon link here ), and some Velcro to attach the arm to back of my iPad cover. That works great, it does not come off easily, it is height adjustable, and it does not take up much space. I also added a small metal tab to hold back the front cover, so
Read more