Near catastrophe event!

[Kitfox Pilot]

We were looking over the Kitfox and I thought the main bolt that holds the tailwheel might need to be tightened a bit, so I took off the inspection cover to get to the nut. After torquing it I told Susan I was going to look things real good in that area. Thank the Good Lord that the tailwheel bolt needed tighten because that made me find a problem that probably would have ended in a very bad way.
Any Ideas what would cause this to break?
This is the trim actuator mounted to the front of the horizontal stabilizer.
I have checked travel and all was good there, no binding. I just can't imagine the pipe breaking like this without repeated bending or flexing of some kind. 450 hours total time.
Has anyone seen this before? I don't care to tell you this gives me a bit of a chill to fly.
Any way be sure and check this location on your Kitfox.

[P Johnson]

We were looking over the Kitfox and I thought the main bolt that holds the tailwheel might need to be tightened a bit, so I took off the inspection cover to get to the nut. After torquing it I told Susan I was going to look things real good in that area. Thank the Good Lord that the tailwheel bolt needed tighten because that made me find a problem that probably would have ended in a very bad way.
Any Ideas what would cause this to break?
This is the trim actuator mounted to the front of the horizontal stabilizer.
I have checked travel and all was good there, no binding. I just can't imagine the pipe breaking like this without repeated bending or flexing of some kind. 450 hours total time.
Has anyone seen this before? I don't care to tell you this gives me a bit of a chill to fly.
Any way be sure and check this location on your Kitfox.

Harlan,

WOW that was a good bit of fortune.

The bracket looks like it has failed with a clear fracture line on it with fresh metal showing but the tube has does not appear to have fresh metal showing on the photo, it looks black like the powder coating?

Paul

[bumsteer]

Harlan

Thank God and a great catch. In case they don't see the post, I'd recommend you send the pictures to the factory, and yes, everyone take a good look-see at that area.

Rick

[dothedr3w]

Let's us know how this one turns out, Harlan. I'd be a bit spooked for sure.

[Dave S]

Harlan,

Man! We are glad you are still with us!

Looking at the space that developed indicates to me that there was lengthwise tension on the tube somehow. Paul's comment that the tube looks like an older fracture and the tab that cracked looks pretty fresh might indicate some kind of stress riser that started on the tube.

Since I am a nose gear kitfox guy with manual elevator tab trim rather than the adjustable HS, I am not familiar with all the hardware items. What does the little link on the front of the assembly do?

On the nose gear, there is a fixed rod with rod ends in place of the jackscrew that holds HS in a neutral position all the time so no link on the second set of holes with the nose gear.

I have not heard of this happening before.

There is a reason we do inspections.

[Kitfox Pilot]

My guess is it has something to do with this. https://www.youtube.com/watch?v=KSoXf7_imrY

I have never had the shakes this bad but I have had the shakes. Many others have too as the higher hp engine are being used. https://teamkitfox.com/Forums/thread...izer-vibration

[Billiken]

I?m glad you found it and are ok. Thanks for posting the pictures. It looks like a failure in multiple spots. I have the same horizontal stabilizer and am now concerned. I?m my opinion, this should warrant a remedy and Service Bulletin. Please keep us posted.

[bbs428]

Not good! Glad you found it because the NTSB would have "after" the accident!

I'm just over 200 hrs. I'll be looking at this closely.

Some thoughts...

80-115 hp. should be ok but warrants a look. Maybe a 100-hr./yearly inspection item or a one time inspection?

130hp and above maybe mandatory every "xx" number of hours?

Maybe less Vx and more Vy takeoffs unless necessary to reduce stress and shake.

Also - Lot's of Kitfox's out there flying and this is the first of its kind that I know of that broke like that. Perhaps some heat stressors because it's by the weld???

[n85ae]

My tail buffets, and always has on takeoff. I have an IO-240B with a 74" Sensenich. Guess, mine's grounded
pending a thorough inspection.

That's a very lucky find, and really illustrates the need to not get too complacent.

I remember my shop in the Navy had a big sign saying "Complacency Kills" over the door.

Jeff

[n85ae]

Looking at that video, it looks like the pilot side is buffeting more than the cp side, so I bet it was broken already.

Jeff