IBBS Mounting

The navigation avionics and engine management systems each have a TCW Integrated Battery Backup System (IBBS). The backup systems provide essential power in the event that one or both alternators in the Rotax 912iS engine should fail. There are 2 battery power units that have to be mounted someplace. I’ve found a spot on the fuselage rib, behind the parachute compartment that is within comfortable reach of the associated wiring harness connectors.

I thought that the batteries could use more support than they would get, were they attached directly to the rib. I designed and fabricated doubler plates to reinforce the rib. The batteries are fastened to the doublers.

I’ve had to consider that one day the battery units will have to be replaced. It won’t be easy, but I will be able to get to them from the front, after I remove the pilot side display and the remote LRUs and vertical rack that sit behind it.

LRU Rack Fit and Mounting

Most of the remotely mounted avionics will be behind the instrument panel, on a custom designed and fabricated rack. Each Line Replaceable Unit (LRU) has a specific position on the rack and the harness is custom tailored to precisely reach and connect all of the units together, along with all of the other electrical systems in the aircraft.

I elected to have the harness and panel professionally designed and fabricated by Midwest Panel Builders in Lapeer, Michigan — specifically for my Sling 2 and its extensive Garmin G3X advanced IFR avionics suite. While I might have been able to manage the panel and wiring for a modest VFR setup, there was no way I was going to attempt it for this project.

Even with the custom-made harness, rack and panel there is still plenty of fitting and integration for me to do. This is no paint-by-numbers ELSA project. It’s full-on experimental amateur-built — all the way. I can’t wait to begin training for my IFR rating in this aircraft.

The LRU rack is a replacement for the one I received back in April. The original rack was the first of an all new design and needed several refinements.

The new rack needed to be fitted and the mounting points established. The center portion of the rack needed support. I designed and fabricated a bracket. Everything fits nicely.

Cabin and Firewall

With the firewall forward kit and the avionics, related tasks are accomplished.

Instrument Panel and Avionics Arrive

Boxes and boxes of Garmin avionics arrived along with my custom instrument panel and its plug-n-play wiring harness from Midwest Panel Builders. There’s lots to play with, but I still managed a few other tasks.

March – Spring Has Sprung

Man does not live by aircraft building alone. There are so many enjoyable things to do.

E-Biking on the Spruce Railroad Trail – Lake Crescent, Washington

Group Fly-Out to Forks, Washington – Mary Ann and I have some fun flying in our Warrior

Misc Rework – Firewall and Wingtip

Work on the RH wingtip continues. Getting a good fit (matching the wing airfoil) is what I’m after. It has to happen in small steps. I’m getting there.

The battery box reinforcement channel is going to be tricky to rivet to the firewall. That’s because the shape of the channel overhangs and blocks access for the rivet setting tool. A few of the holes can be riveted from behind, but a couple holes are only accessible from the front. I’ve asked the factory about it. (This channel really should have been mounted before the parachute box was assembled at the factory.)

I’ve decided in favor of having the full-airplane ballistic parachute. I’ve thought about it – long and hard. The terrain in Pacific Northwest Washington is very rugged – utterly unforgiving should the occasion of an emergency off-airport landing ever present itself. Having the parachute will give me some peace of mind. I think it will also open the door to some evening and night flights that I wouldn’t otherwise consider.

The parachute system adds weight and expense, but it likely adds a bit of safety margin and value, as well.

There are break-away skin panels that cover the parachute compartment. Mounting them will involve countersunk rivets. The flanges of the firewall, RIB-003 and the curved top-skin, in front of the windscreen need to be dimpled with a squeezer. To do that, I have to remove the top-skin that was partially riveted at the factory. I also have to countersink some of the holes in the narrow cowl mounting strips, using a 120 deg pilot-cutter and micro-stop cage. I’m doing this countersink rework on the plane, so it’ll be a freehand operation with my lithium battery-powered drill. Having the top-skin off will provide improved access for installation of the avionics rack and wiring harness.

The Engine – Rotax 912iS Sport

I have to say, it looks suspiciously like — a brand new airplane engine!!!

Admittedly, there’s not much building going on here, but there are some cool details to look at. The engine comes with its Engine Control Unit (ECU) – the computerized module that monitors and manages the engine performance. There’s a fusebox and dual voltage regulator module. And, there’s a completely assembled fuel pumps module. Early Sling 2 kits apparently required building up the internal plumbing with two 2 pumps, check-valves, hoses and clamps. I’ve been spared all of that. Each modules are matched to the engine serial number and were presumably used to test run the new engine (for about an hour) at the BRP Rotax engine factory in Austria.

There are some small parts for specialized electrical connectors that I’ll send off to my wiring harness builder for incorporation. There are also some bushings and hardware for mounting the Whirlwind propeller, which should arrive in a few days.

Custom Instrument Panel – First Look

A lot of thought has gone into the instrument panel. With two 10″ Garmin G3X Touch displays, remaining Sling 2 panel space is at a premium. I still needed to tuck in a GTN 650Xi navigator, GMC 507 auto-pilot control and a G5 backup flight instrument. With all that gear, finding places for switches and circuit breakers took me a while to figure out.

A Vertical Power VP-X Pro, solid-state circuit breaker system, completely eliminated panel-mounted circuit breakers. The arrangement of the quite modest number of switches has been carefully laid out. Workflow and purpose were key considerations. I’ve taken advantage of advice and feedback from many sources. So far, I think it’s turning out beautifully.

There’s a tremendous amount of functionality in the touch-screen avionics. That reduces panel clutter enormously. Remote GTR 20 VHF (COM2) radio, GTR 245R audio control and GTX 45R ADS-B (in/out) transponder are all managed through the touch-screens. There’s also integrated engine monitoring and display.

There’s so much stuff, that getting a professionally designed and fabricated wiring harness is clearly the only way to go. The absolute top shop for this work is Midwest Panel Builders in Lapeer, Michigan. They’ve been setting the standard, especially for the various models of Sling aircraft.

The integrated capability of all this equipment is truly astounding – off the charts compared to more traditional steam gauges that have been the mainstay of small GA aircraft for decades. I simply cannot wait to slip into the cockpit and learn how to put this technology to effective use. It’s going to be huge fun. My plan is to earn my instrument rating in my own technically advanced airplane (TAA) . That’s a thing, believe it or not.

Rotax 912is Sport Engine – New in Box

Big Wednesday kicked off with a scenic morning drive from Sequim to a freight forwarding company in Kent, Washington. My engine and firewall forward kit was shipped Cargolux air-freight from South Africa, changing planes in Belgium. The goods arrived a couple of days earlier at Seattle-Tacoma International Airport (KSEA, SeaTac). Having cleared customs, it became available for me to collect.

I’ve looked forward to a day like this for I don’t know how many years. Having an absolutely brand new airplane engine is almost too much for me to grok. I’ve been harboring thoughts of rebuilding the O-32O in my ’84 Warrior, almost since the day I bought it 20 years ago – but, it hasn’t happened. It’s still running strong at TBO. And now, I’ve got the Holy Grail in hand – a factory new airplane engine! Oh my!

This new engine and the Sling 2 airplane I’m building are a match made in heaven – 21st century all the way!