Trim tab

I took a little time for shop clean up tonight, now that the engine is not hanging on the hoist anymore. After that I worked on reinstalling my new trim tab. As you can see on this post, I had to make a new one since the old tab was cracked due to a bad modification which led into fatigue.

Before installing the new tab on the airplane, I applied transparent polyeurethane erosion tape on the bottom since it is highly exposed to prop blast. Here is how the bottom of my old tab looked like when I removed it:

One other thing I realized when I removed the old tab was that the attachment holes on the piano hinge were badly ovalized:

Again, this demonstrated to me how little details can be very important. The old screws were standard AN526 SS screws with almost zero shank length. The S-1S parts catalog calls for screws with a small shank so that no shear load is applied on the thread. I'm pretty sure that if the correct fastener was used, my old aluminium piano hinge wouldn't be as bad. I decided to replace the crews with AN 525 washer screws. You can see the subtle difference between the two here:

Here is a shot of the final installation compared with the old tab.

Again, big thanks to my friend Paul who patiently helped me building the new tab. Thanks also to my friend Joe who helped me with the paint (I hate painting).

Engine back to where it belongs

Yesterday I finished assembling the firesleeves. Sliding them on the hoses was easy when the hose was with straight or 45° ends, but impossible on a hose that has two 90° elbow hose ends. Perhaps I should have chose bigger firesleeves for these hoses... Anyway, two of them were like this so I had no choice but to dismantle one end for these. Note to myself: install the firesleeve before assembling a hose with two 90° hose ends!

Installing the SS zip ties went smoothly with a special tool I borrowed to my friend Scott. I followed EAA video here to install them.

Today, I installed the hoses on the engine and made the last checks to make sure the engine was ready to be reinstalled on the fuselage. Once ready, I could finally roll the hoist towards the fuse. I asked for the help of my father to align everything up. Thanks dad!

With the bolts in place in the fuselage, we found that using Quick Grips to gradually squeeze each of the four engine mount attachments to the fuse worked quite well. The engine leveler helped a lot to adjust the pitch angle of the engine. After about an hour, all four AN6 bolts were securely fasten with their cotter pins. It felt so good to pull the hoist back and lower the tail. Here is what my little bird looked like at the end of the day:

 

As you can see on the floor, I had my fuel tanks painted by a new friend of mine, Jocelyn, who kindly offered me to paint them in his paint booth. Thanks Joe! Here is a closer look:

With the engine installed, it opens the door for many other tasks like fuel system installation, engine controls, electrical system, etc. I am not sure yet what I will start, but it's getting exciting!

Hoses replacement

It was much longer than I anticipated, but last week-end, I finally completed the rebuild of FWF hoses. Here is a picture of all the old hoses with the firesleeves that I am also replacing:

I started working on the new firesleeves today. As mentioned in my previous post, I am protecting more hoses than before. I first used a pair of cissors to cut them to length but found it made a better job using an x-acto. Here are the main ones:

I then made a mix of RTV sealant with MEK to seal the ends. 50/50 gave me a good result:

I then transferred the mix into a smaller cup and dipped each firesleeve end in it. Here is what it looks like:

I am getting close to being able to put the engine back on the fuse. I worked quite a bit on my firewall a few weeks ago and installed/changed many nutplates. The fuselage is ready to receive the engine back:

Next step is to install the firesleeves and reinstall the hoses back on the engine. Stay tuned!

Back to work

It's been a while since my last post. Went on vacation, got sick and slowly recovered. I can finally resume my work on the Pitts : )

Been working quite a lot these days to replace all the hoses FWF. I checked the logbook and my hoses were all 10+ years old so I decided to change them. The hoses are all steel braided and hose ends are all Aeroquip 816 type or equivalent. I wish I could afford all brand new hose ends and fittings but they're just too expensive so I'm only changing the steel braided hoses and reusing the hose ends.

First had to purge the oil from the engine and start removing hoses. Some hoses were "fire protected" with a fiberglass sleeve attached with lacing and tie-wraps:



I didn't find this very smart for two reasons. First, plastic tie-wraps will quickly melt in case of fire and second, since there is no silicon wrap around it, it doesn't prevents contaminants like oil and fuel to soak the fiberglass and turn it into a fire hazard rather than a fire protection. As you can imagine, I bought proper firesleeve material and will replace the old fire-enhancing sleeves...

For each hose, I carefully remove the hose ends using special bench vise jaws and a wrench:



Then I cut the new hoses using a small metal cutting saw which allows nice clean cuts which makes my job easier later to reinstall the hose end:



After that I reinstall the hose ends using the technique recommended in this EAA video.

Doing this for all hoses is time consuming. I did all the oil hoses already and just started removing fuel hoses. I realized that due to lack of lubrication, fuel hoses get much stiffer over time than oil hoses.

I'm about 50% done now. Will post an update once complete!