Brake Lines

I’m not very impressed with the plastic brake lines that come standard with the Sling. Following the vans forums I came across Tom at https://www.tsflightlines.com/ who makes custom brake lines. It took a lot of measuring and samples but in the end Tom came up with a great kit that hopefully he will be offering to other Sling 2 builders.

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Elevator Pushrod Problem

I ran into another Sling gotcha last week, and this one is a serious safety problem if you build it wrong (like mine was).

Recently they redesigned the elevator pushrod guide block assembly for the Sling 2 (and I think also for the Sling 4 and Sling TSI). This is on page F7 of the Sling 2 manual and as usual the manuals have not been updated with this change. I purchased my fuselage as a quick build so didn’t install this guide block, but last week when installing the elevator pushrod I knew that something was major wrong. The pushrod would catch and release and had way too much friction. I don’t think that an airplane in this condition would be flyable.

The new bracket has a taper so that the pushrod and the bushing are aligned, but in my case they installed the bracket upside down so that the pushrod was at an angle to the bushing. You can see that in the 1st 2 pictures that I uploaded.

I was able to get a CAD drawing from the factory that shows how it should be installed. Also is a image of mine after I turned it around and have it almost fixed.

What a pain to fix it with the fuselage already put together. You have only the access hole in the bottom to work through. I used a small camera hooked to my laptop so I could position my drill to drill out the top 3 rivets, punch them out and re-rivet it.

What a drastic change once the bracket was installed correctly, night & day difference.

Totally unacceptable that the factory is making design changes without having documentation released at the same time.

Here are images showing both the wrong and the correct orientations.

Exhaust

There is a lack of instructions for the exhaust system and the pictures that they show is not accurate. So after discussion with the factory I found that it is necessary to make a slot in the lower cowling for the tailpipe. But a better solution would have been to route the tailpipe between the 2 lower motor mount brackets and then it would be far enough away from the cowling to avoid the need to cut a slot. BUT I had already riveted on the heat shroud so I can’t do this better option. So for anyone out there reading this don’t install the heat shroud until the end when you know exactly how you plan on mounting the exhaust system & the tail pipe.

Liquid Cooling & Heating

Living & flying in Wisconsin I want to make sure I have a heating system that will keep me warm so I can fly in the winter months. Midwest Build Center came up with a mod to use the liquid cooling system to supply warm cabin air via a radiator mounted above the pilot’s feet. Hopefully it works well. The 1st picture you can see that I rotated the outlet on the back of the engine to get me a straight path to the radiator mounted on the bottom of the cowling. The blue hose in the pictures is for the cockpit heating.

Fuel System

Here is just a couple of pictures of my fwf fuel system layout. Midwest Build Center suggested I buy this part from Lockwood aviation (AC-LLC-269iS block with restrictor fitting).  It has fittings for both the feed and the return lines and also a restrictor valve so replaces quite a few “T”s, connections and short hoses.  Some other comments:

  • Make sure you use the correct size of fittings & fuel line. Usually AN6 fittings work with 3/8″ fuel line but here we have 5/16″ fuel line. Also make sure you use fuel line for fuel injection if you have the 912iS engine.
  • The gascolator that came with my 912iS engine kit is the wrong one. It is for a carb engine that has lower fuel pressure. You need to buy the high pressure one: https://www.aircraftspruce.com/catalog/appages/gascolators1.php

Firewall Penetrations

I am not very comfortable using plain rubber grommets for all of the penetrations through the firewall. Doing research I found this very helpful forum post http://www.vansairforce.com/community/showthread.php?t=72087

I used both some stainless steel closet pole brackets and also a stainless steel flange that I found on ebay. I know that there is more that I could have done, for example the heater box is aluminum and will be a weak point.

Here are some images of work in progress. When done I won’t have any rubber grommets in the firewall.