Rotax 915iS vs 914UL: Cost and Technical Differences

By request, here’s a breakdown of the technical and cost differences to equip my Sling 4 with a Rotax 915iS engine instead of the Rotax 914UL engine. As a quick reminder of why I’m doing this: +26HP at takeoff power (5800 RPM), +35HP at max continuous power (5500 RPM),...

Update on Flaps Controller

I’m waiting on the circuit cards to come back from the fab, likely slightly delayed due to the holidays. In the interim, I worked on honing the process for painting and etching the fascia panel. My second iteration is looking better than the first, but I still need to...

Fabricating Flaps Controller

I shared the design concept for my custom flaps controller a few weeks ago, and I got some great feedback from other pilots & builders. I’ve taken that feedback and made a revision 1 of the hardware, to include: Stand-alone operation (no additional parts needed, connects directly to the...

Engine Arrived

My engine arrived today! This is the Rotax 915iS engine, and as I described in an earlier post, this particular engine is used with just 12 hours on the clock. Even though I bought it locally, it was inspected by Lockwood Aviation down in Florida, as they are currently...

Flaps Controller

I prefer controls that provide visual cues of their current setting. I have a minor in Human Factors from my undergraduate days, and one of my professors was quite passionate about aircraft. As a result, I really don’t like using up/down toggles that are so commonly used on experimental...

Heating System Demo

I posted a video on YouTube recently with an early demonstration of the my heating system. Everything is functioning the way I expect so far, and I’m continuing to work on the software. I’m quite impressed with how much air it can move. Here’s a link to the video,...

Welcoming Home the First Sling 4 on the East Coast!

14 November, 2020 I recently had the honor to attend the big homecoming celebration for my friends and their newly-completed Sling 4! A huge achievement for Craig & Ellen, who have been looking forward to this day for 6 1/2 years! Before landing Craig did a little fly-by so...

Replacement Wing Skins

I received a crate today from TAF in California, containing my replacement wing skins! I’ll be able to finish off the right wing now. One of the skins is the leading edge for the fuel tank, for which I’ll need to order some fresh FlameMaster sealant. Between these skins,...

Engine On The Way

Coming soon to my workshop: a Rotax 915iS engine! Those familiar with the Sling lineup know that the 915iS engine normally is found on the Sling TSi, not on a Sling 4. So, my airplane is going to be somewhat unique, but that’s part of what experimental aviation is...

Heater System Prototype Progress

It’s pretty exciting dreaming up a concept, turning it into a design, and then having a working prototype in your hands, all in the course of a few weeks. I recently watched a video about the new Diamond DA50 RG, a 4-to-5 place retractable gear single engine airplane that’s...