Uh Oh!?

Strappe · #1 09-17-2019, 08:09 AM

I was working alone and frustrated that I couldn't find someone to help me readjust out RV-12 on the saw horses in order to get an inch or two more ground clearance on one side in order to re-install the wheel. So I had this brilliant idea that I could get closer to the aft sawhorse, raise it with my back against the bulkhead in that area, and shove another rug under the aircraft on top of the sawhorse.

It worked, but just as I began to lower it, I hear a loud pop followed by the tinkling sound that a small piece of metal makes against an aluminum panel. The link I have shared (I am not permitted to upload images as attachments) shows the rivet head. It also shows an area on the bulkhead closest to the sawhorse location where four rivets are missing. I have not yet found any portions of any rivets on the floor around that area or anywhere else.

I am very worried that my utter stupidity has led to a big problem, but I also wonder if during prior inspections, I just didn't notice the missing rivets.

The bulkhead is easily accessible for inserting new rivets, and it appears the holes are nearly all lined up (the upper one looks a bit out of line). I have contacted our local EAA RV-12 guru to come take a look and advise me. I also would value the thoughts of y'all on this forum.

Strappe · #2 09-17-2019, 08:15 AM

Here's another effort to make images available: https://photos.app.goo.gl/RUWA4aT1wHmiJVuYA

bkervaski · #3 09-17-2019, 08:18 AM

No expert but I did stay at a Holiday Inn last night. Unless I'm missing something all you can really do here is install the rivets and move on.

rongawer · #4 09-17-2019, 08:42 AM

I agree; cleco that sucker up and install rivets.

Definitely take a good look at all the metal around it to ensure no deformation of adjoining structures.

Mich48041 · #5 09-17-2019, 01:16 PM

If 3 rivets were never installed, then it is possible that you broke the one that was installed. But it is unlikely that you broke 4 rivets.

rgmwa · #6 09-17-2019, 04:17 PM

FWIW I think Joe's probably right. I'd check carefully for any damage, then cleco from the bottom hole up and install the rivets.

rcarsey · #7 09-17-2019, 09:33 PM

Quote:

Originally Posted by Strappe

It worked, but just as I began to lower it, I hear a loud pop followed by the tinkling sound that a small piece of metal makes against an aluminum panel.

The first thing to pop (pun maybe intended) into my head isn't that I broke a rivet. Why? If it broke because from tension, I think I'd expect to see the metal around the rivet head deformed a little before the rivet gave way. Or, if broke from shear, I'd expect to see the remnants of the rivet still in or right next to the hole. In either case, it would take a lot of leveraged force to break a rivet.

Do you have any clecos still installed anywhere? It it possible that a cleco wasn't fully "seated" and by jostling the plane, a cleco snapped into place and created that loud noise? Or perhaps that rivet head was sitting in one of the tail's J channels and fell out, hitting the bottom skin. (is it a real head? or a drilled out head? sorry, have to ask!)

RFSchaller · #8 09-19-2019, 07:45 PM

If the parts aren?t deformed I?d mutter a few choice epithets, install the rivets and move on.

BMC_Dave · #9 09-20-2019, 09:48 AM

No way you sheared those rivets without deforming the metal around them, they were never installed. I'd do a double take now to make sure nothing else is missing, install and build on...

Strappe · #10 09-21-2019, 04:48 AM

Thanks to all for your insight and advice.

This is a 2015 RV-12 with 200 hrs on it, 120 flown by my partners and me. We bought it in 2017 and this was the second maintenance and condition inspection for me after getting my Repairman certificate.

After crawling into the tail and getting a close look at the area of 4 missing rivets, I found that 3 of the holes clearly never had rivets installed. The upper hole had a slight hint of a mark, but I doubt there was had been one there either. As you all know, the only rivets that have heads on the inside are the ones in the bottom of the bulkhead horizontal union and some smaller rivets where the longerons (? if that's what they are called) join. None of those are missing or broken.

Not sure what the pop was other than flexing of the sheet metal. I believe the metallic clink was a stray rivet head left behind long ago that got bounced when the sheet metal popped.

I installed the 4 rivets, took one final look around, mopped up the puddles of sweat (is there any place on Planet Earth hotter than the fuselage of an RV-12 during a Nebraska summer?), buttoned things up and went flying.

Thank you all again!