Tag Archives: jig

Engine Cowling – Initial Trim and Fit

The composite engine cowling is one of the key contributors to the look of a Sling aircraft. I love the way Slings look. There are other models available from Sling Aircraft now, but it’s the Sling 2 that started it all. Now my Sling 2 is starting to look like it should.

There are a few pointers in the plans about the cowling, but mostly it’s up to the builder to figure out how to get the cowling to fit – properly and securely. I’ve complicated the process by introducing a custom spinner assembly. The factory-supplied spinner, while likely adequate, has to be built up from parts. The spinner I ordered through the propeller manufacturer – Whirlwind – is beautifully made from carbon fiber, comes finished and ready to paint. It’s a slightly different look, but still very, very Sling-like.

The 9.75″ Whirlwind spinner is notably different from the factory unit. The backing plate flange faces backward instead of forward. This will mean that the cowl will have to fit somewhat farther back on the fuselage than it otherwise would for the standard spinner.

To get the cowl aligned and with the proper setback, I’ve made a fixture that mounts to the prop hub extension. The hub extension is a standard part of the kit. Repeated fitting and trimming will hopefully arrive at a near perfect position and alignment. More to come on that.