Prepping More Wing Parts

Time: 1.5 hrs

Just a quick post on some progress on the wings. I cleaned and primed a few parts for the ailerons (and some fuselage access panels). So work has officially begun on the wings.

Some aileron and fuselage parts primed in my spray booth 🙂

Wing Parts Prepping

Time: 7.0 hrs

I suppose I should start this post by saying that this weekend sucked. Sunday morning I found out that a pilot friend of mine had passed away. His plane went down about 60 miles North of here in Porter Ranch on Saturday morning. I’m in such shock about his passing. He was a great guy and amazing pilot with military and professional experience. I looked up to him as a mentor. We don’t yet know what happened… some have speculated it was a medical issue, but I suppose once the NTSB is done we will have some answers. You will be greatly missed Dan.

Dan Delane, then the chief pilot for FedEx in Los Angeles, is shown in a 2013 file photo. (Photo by Brad Graverson, Daily Breeze/SCNG)

Well back to the Sling building. Today and yesterday I started working on the wings. I will need to build them on my rear porch since I don’t have room in the garage… not sure where I will store them yet. I pulled the plane out of the garage so I could clean some things up and move the work benches out to the porch. I also used the opportunity to test fit the wing spars. To my absolute amazement the spars fit. The right side seemed like it wasn’t going to fit at first and it’s a tad tight, but it will work fine. The left side fits perfect. So a big relief there.

I began work on the wings by first assembling the wing jigs… pretty straight forward. The main and rear spar will get mounted to it and then they need to be leveled in respect to each other. The jigs hold the twist in the spars so the wings are shaped correctly. I’m not ready to mount the spars in the jigs yet so will get to that in a bit.

There are a ton of parts to prep (2 of everything). I deburred the parts for the ailerons, rear spar, and started on the main ribs. After I get a few things prepped I’ll prime them. I’m going to prime all the surfaces in the wings since I don’t want to have any issues with corrosion. The plan is to get the ailerons mostly assembled (finally skin riveting is done with them attach to the wing so they match the twist), Then that flaps (if I get the parts soon), then start of the wings.

A pile of ribs. These have been demurred and I check the fitting of all the attaching parts.

Wing jigs done. A set for the left wing and a set for the right.


Misc Wiring

TIme: 1.0 hr

I received some wire and wire sleeve that I ordered so I finished up a few things. I put some wire sleeve around the wires in the fuel pump to protect them from rubbing on anything in the fuel pump box. I also finished running the wires for the turbo boost and warning lamps. For these I cut off the connector on the wire coming from the engine and then used a solder sleeve to extend the wire. The lights will be mounted on the instrument panel on top of the PFD next to the Servo ISO switch and Reversionary switches. Lastly I ran the 8 or so 22AWG wires from the VPX for the various switches.

Sorry no photos

We Have Wings…

Time: 2 hrs

Today I picked up my wing kit from Torrance TAF. There’s a lot of parts… while I inventoried the parts I started thinking wow this is going to be a lot of work. I’m hoping the build goes smoothly and things go together quickly. After the wings are built, I’ll be pretty close to getting the paint done (I guess I better get a paint scheme designed). It will be nice to be able to do some riveting again, I can always go back to doing avionics in the fuselage if I get tired of it. I really don’t have the room to build the wings let alone store them. My wife was nice enough to say I can build them in the house so that’s probably what I’ll do. I may see if I cant rent a storage unit down the street where I can builded them, but I suspect the storage unit will cost close to renting a hangar.

After I did the inventory I found that this kit is missing quite a few parts. Some were pillaged for other customers, one skin was damaged (fairly large deep scratch), and the rest just missing. The one bummer is that it looks like the wing spare might not fit in the opening in the fuselage. Since I didn’t have the wings yet I measured one at Torrance TAF and made some wood spacers. They were a pretty tight fit I remember, but it seemed right. The real problem that I was told was that the open was going to be too large and when you tighten the spare bolts the skin will buckle a bit, well it seems mine is the opposite. It’s seems like it’s really maybe 1/64″ or less, but I’m thinking it’s not going to fit. I’ll have to roll the plane out and try to fit the spares in the next few days. if they don’t fit I’ll have to start drilling out rivets and seeing if I can get it to fit. Not much fun so I’m praying it will fit.

The spares in the long thin box and the rest of the wing parts in the large box. I think it’s more parts than the fuselage.

Fuel Pumps Finished

Time: 2.5 hrs

Well finally I got the fuel pumps installed. There was a lot of trial and error to get everything worked out. Fortunately the pumps all fit in the Rotax box and the placement of the mounting screws worked out as well.I also have all the fuel and oil lines in (just need to torque the fittings).

I decided to change the way I had mounted the pumps to the mounting bracket. I was using the two adel clamp that came with the pumps, but I change to using for stainless steel zip ties instead to make the pumps a bit more secure and save some room. I just needed to drill a few holes in the mounting bracket so that the ties could loop around to secure the pumps. I purpose some ratcheting ties which worked great. it was much easier to get a nice tight pull on the ties.

I like the zip ties better better than the adel clamps and then don’t take up as much space either.

It’s mounted and wired up. I also put in the Capacitors using some crimp on ring connectors. Negative is a M5 screw and positive is M4.

A few photos of the fuel lines (all stainless steel). Everything is roughed in. I just need to make sure all is good and the I can torque the fittings and secure any wiring like for the fuel flow sensor.

Avionics Wiring Continued

Time: 4 hrs

Over the past fews days I finished up most of the wire runs for the avionics that I’m mounting on the shelves and rib. I also terminated all the grounds to the main grounding block. I’ve been trying to understand the way Garmin has set up the grounds on the avionics. It seems like most of them have redundant grounds. I’m not sure if it’s just for redundancy or if they actually need to be connected to function properly. It seems like a few actually do need the multiple grounds connected like in the case of the transponder, but most seem to be merely for redundancy. I’m planning on only doing redundant grounds on the “essential” equipment since I’ll probably run out of connections on my ground bus.

I’m going to get the connector kits for some of the avionics so I can start wiring them up. I don’t have the money right now to get all the avionics that I need so with the foam mockups and the connectors I should be able to get everything wired up. When I do get the avionics it should go very quick getting them installed.

I’m also wondering if I need to wire in connectors for the avionics that will be mounting to the instrument panel. It seems like it would be good to do so that the whole panel could be more easily removed, but I don’t want to add in more potential points of failure. I guess I’ll need to think about it a bit more.

Upholstery is Here

Time: 3 hrs

The big news is the custom upholstery that TAF did for the plane arrived and I picked it up from Torrance TAF yesterday. I couldn’t wait to see how it would look in the plane so I put a few pieces in the plane. I’m so happy with the way it came out, they did an amazing job.

I also had to put an O-ring back in the hose inlet for the cooling (it fell out when I had taken it off to turn it and put the hose on). Fortunately I found it when I was cleaning up the garage and kind of put 2 and 2 together. I looked at the IPC for the Rotax and sure enough there’s an O-ring show in there.

The other work was mainly cleaning up, organizing, and labeling wires. Oh yeah and I installed the arm rest.

A few photos of the interior. Nothing is installed yet. I just wanted to make sure things fit and wanted to see how it would look.

This is the O-ring that fell out when I took the inlet off a few weeks ago. I’m just glad I thought about it when I found the O-ring and didn’t just throw it out.

Fuel Pump Assembly and Pressure Test

Time: 1.0 hrs

The fuel pumps went together quickly. I purchased some Oetiker ear type clamps from Belmetric. I purchased 14.5mm and 19.8mm size clamps which seemed to fit well. The 14.5 were a tad tight over the fittings, but I was able to get them to work. After I had the pumps assembled I used a differential pressure tester that I purchased from Sky Geeks as well as some extra fittings and a hose that has quick change connectors on the ends (the hose that comes with it one has quick change on one end). This pressure tester can also be used to test the pressure drop on the 914 cylinders using a 12mm adapter to connect to the spark plug hole which may be handy in the future when I do my annuals.

I tested the fuel pumps for leaks up to 30 psi. I found that the Rotax docs for the rubber rebuild on the IS (fuel injected) type engines tests the pumps up to 87psi, but the carburated engines don’t run at as high a pressure, the normal fuel pressure is around 2-5psi over the airbox pressure (which is max around 18psi). I didn’t want to damage anything so I figured 30 psi would be reasonable. The only leak I had was on one of the adapters I used to get the tester connected to the -6AN fitting on the pump. I’m happy that the 5/16″ hose barb to -6AN converts I found don’t leak. Now I have AN fittings on the pumps and don’t need to use rubber to run out of the pumps to connect to the stainless steel hoses.

Just a quick check I ran the tester up to 10psi and set the slow fill back to off. I noticed the pressure dropped off on the second gauge after a few minutes so I knew there was a leak. It turns out the leak was between the M14 adapter and the M14 to -6AN fitting. I was able to tighten that up again and ran the test up to 20, then 30 psi. I left it for about 5 minutes with no noticeable pressure drop and a check with some soapy water on all the fittings just to make sure.

Fuel pumps all assembled and fit into the Rotax fuel pump box. I’m going to check with TAF to see if they have a been made bottom plumbing manifold. I noticed from Craig’s build log that his has a better, tighter bend to it that would fit much better in the Rotax box than the one I have. Also I may work on a better way to attach the pumps to the mounting plate. I’m currently using the clamps that came with the pumps, but I don’t like that I had to mount them towards the ends of the pumps to avoid the screw from hitting the check valves. It’s such a tight fit to get all this stuff into the box. I would prefer more centered so the pumps are more secure or using 2 clamps per pump.

A photo of the differential pressure tester (model E-2A) I got. Aircraft Tool Supply has them as well, but they were out of stock and it wouldn’t have been available for 3-4 weeks. This is the 0.040 orifice one with no master orifice. The hose is the ATS extension hose which has quick disconnects on both ends so I was able to purchase a 12mm (for the cylinder compression checks) and a 14mm (to make the conjoin to the fuel pumps) with quick disconnects that can be swapped out easily. I chose a 14mm adapter just because I was able to find an M14 female to -6AN male fitting.