Service Bulletin SB 18-09-17

SERVICE BULLETIN 18-09-17

Date Released: September 17, 2018

Date Effective: September 17, 2018

Subject: Cracking of the F-01478 Aft Fuse Forward Bottom Skin

Affected Models: RV-14/14A empennage kits shipped prior to 9/26/2018

Required Action: Inspect the F-01478 Aft Fuse Forward Bottom Skin for cracks at the aft ends of the F-01486C-L & -R and F-01486D J-Stiffeners in the area of the F-01408 Bulkhead. If cracks are discovered, complete the modifications described in this document. If no cracks are discovered, annual inspections are required.

Time of Compliance: Inspect at or before the next annual condition inspection. If no cracks are detected, re-inspect at every annual condition inspection, or until the modifications described in this document have been completed.

Synopsis:

Cracks have been discovered in the F-01478 Aft Fuse Forward Bottom Skin in the area of the F-01408 Bulkhead propagating from the aft most rivet in the F-01486C-L & -R and F-01486D J- Stiffeners. These cracks have been discovered in the factory RV-14/14A aircraft, as well as some flying aircraft in the field.

Empennage Kits shipped after 9/26/2018 are not affected by this service bulletin.

The F-01408 Aft Fuse Bulkhead is the second one from the front in the photo below.

Below, I've clecoed the brackets in, getting ready to match drill the bulkhead.

Left side F-01408 Bulkhead match drilled to the F-14147-L bracket...

Left side F-01408 Bulkhead match drilled to the F-14147-R bracket...

Routing WH-00059 Comms Cable

This was one of those times when I should've read ahead a little more. After installing the Aft Fuse Wiring Harness, the next step was to install the WH-00059 Phone Cable using many of the same plastic ties. I guess it didn't really cost me much time, just a little inconvenient.

Hmmm, small connector...smaller grommet. 

Had a little extra wire here so had to loop it once to make it tidy. I'll remember this as signal wires sometimes don't like to be looped and they may cause issues.

Not sure why I took these photos, but they may mean something in 10yrs so I'll leave them here.

Aft Fuselage taking shape

The next step is to install the WH-00057 Aft Fuselage Wiring Harness prior to installing the side skins. First, all the grommets had to be installed...

Just to show the order of the bulkheads...

The smaller braces are only resting in the grooves in the bulkheads as these all get riveted at the same time as the skins.

Same with all the horizontal braces - only held in with clecos.

Bottom of the F-01408 bulkhead...

Bottom of the F-01410 bulkhead...

And the most impressive of them all, the F-01411 bulkhead...

As everything is just clecoed in place at moment, I decided to install a diagonal brace to take some of weight off the smaller flanges of the larger F-01407 bulkhead...

I'm this cloth tape has many uses, but I was an engineer working in the automotive industry for almost 10 years, and this tape was awesome at reducing vibration, noise and damage to wires against sharp edges. I ordered quite a few roles of the stuff and started winding...

Priming Aft Fuselage Skins

Cleaning and priming of the largest pieces of the aft fuselage complete.

I'll have to store these ones down below for now.

And these side skins will be clecoed on the frame very soon...

This is the F-01479 Aft Bottom Skin - the tail wheel support tube will poke out the slot at the far end.

All cleaned, primed and dimpled.

Aft Fuselage Top Skins

It's a little early to be thinking about installing the top aft fuselage skins, but I thought I may as well get them all prepped, primed and dimpled at the same time so they're ready to install when I need them.

I begun using a small sander with a piece of Scotchbrite pad cut to the size of the sander - much easier and quicker.

I also taped up the outside of the skin rivet holes so no primer would spray through onto the outside skin.

Bellcrank Assembly to F-01407 Bulkhead

While attaching the bellcrank assembly to the F-01407 bulkhead, the upper AN470AD4-4 rivet shown did not set straight as the pneumatic squeezer caught the closest nut plate and twisted at the crucial moment. A slight wave around the base of the rivet can be seen below.

This is the other side showing the proximity of the nut plate.

and this angle shows a slight bend in the top of the flange adjacent to the top right rivet.

I had to remove the rivet and try different ways of holding everything in place. Below I'm seeing if a 1/2 inch clamp will restrict access.

And then see if the squeezer can fit also....

Below is the new AN470AD4-4 rivet about the be set.

Much better. No kinks in the bulkhead.

Probably could've done with a sand and more primer, but at least the bulkhead is straight now.

This angle shows a much better set rivet and no bends in the flange.

Really not much reason for this image except for the way the flush rivets blend perfectly inside the countersunk flange.