SonexBuilders.net

Hello.
New to Sonex, bought 136YX in FL and it flew to SC. Doing some transition training and on final the throttle cable snapped right where it is connected to the hand lever bolt. Cable was installed between two washers as manual shows. Nut was very tight and hard to get off.
A&P at this airfield said he was surprised to see flex cable instead of solid wire. I see manual offers both types.
If I order new what is the most common out there in use ?
Has anyone else had premature failure like this ? Mine has 209 hours, is model built 2010, always hangared.
Thanks
Ed

It's not the first time this has happened. Perhaps Mr. Mika will share his OSH story :D

It's probably best to install something using quality components for the throttle...

http://www.aircraftspruce.com/pages/ap/ ... -12631.php

That was probably very exciting! After years of flying and assisting in annuals on my 172, I learned that the nut holding the two washers may not need to be dead tight, in otherwords, tight enough to cause the inner diameter of the two washers to act like cutting surfaces. The cable used was indeed the solid type, and I never saw any cessna I assisted on with a flex cable. With this in mind, I purchashed a cessna style push-pull control for my throttle, and upsized the diameter of the inner cable/wire to as large as was available. I am pleased with the functionality, even tho I had to install a motion reversing arm on the firewall. In my opinion, this is one of those areas where over engineering...so to speak...should be considered. The retaining bolt and nut, with the oversized wire, still should not be overtightened., but for sure tightened enough so as to not slip with rough motion reversals. And, remember to turn the last 1/4-1/2 inch of the free end to a 90 deg or so angle to prevent the cable coming completely out of the retaining nut if it should lossen, even with a stop nut applied. This should be one of the prime inspection points when doing a condition inspection too! All above is, of course , IMHO!!! :D

Ed,
Thanks for sharing your service difficulty here. As I am about to buy components for throttle control I'd be interested to hear what you do next. Joe, I'd also love to see some pictures of your reversing mechanism.

I would be glad to. I will be at airport with grand daughter this afternoon, and will attempt to remember to take a pix or two. Do you wish a PM or else I probably would need assist on posting pix here. Just getting ready for taxi test or two to put a few more mins on the engine so cowling is off..not really built either!!

Joe,
I'll PM you my email address and with your permission I'll post the photo in an appropriate thread. For anybody on Sonexbuilders that wants to email me my g mail account is my first name, last name, and serial # all jammed together.

Thanks! I should be able to get the pix to you this evening!

Hi Everyone,
Yes, I had my throttle WIRE break on base while landing at OSH 2012. At some time during the flight, the rotating part in the throttle assembly bound up and the wire began to bend at each adjustment. I was VERY lucky. Here is a shot of me and the Sonex Crew removing the WIRE and installing the CABLE.

https://www.flickr.com/photos/50734158@ ... 790558074/

Here is a video of the landing:

https://www.youtube.com/watch?v=oKo499aWSCw

One of the things on my Pre Flight check list is to feel the cable at the throttle assembly to make sure it is not frayed.

Bob (Being watched over) Mika

Thanks
I have ordered the new larger diameter cable.
Ed

Hi all,
We are using the side mounted sonex throttle quadrant, with a high quality cable from ac spruce. ($100 ? ) it is cable at one end and a threaded housing at the forward end to the rotec tbi. Works well. Yes ive been watching about a few throttle cable breaks , hence our set up. If i remoember correctly if you are using a sonex cable w aerocarb it has a swaged ball for the tbi? As bob mentioned, a good part of the preflight move the throttle and inspect where it connects.

WaiexN143NM
Michael