11.1.5 Premolded NACA Scoop Installation

The openings for the two large scoops are embedded into the fuselage at the factory. I still need to cut out the openings and prep them for installation of the actual scoops, also pre-made at the factory. The small center scoop gets installed later and is used to bring fresh air into the cockpit.

IMG 2184

These two large openings are for the "NACA scoops", seen at the top of the photo, which are used to feed cooling air into the engine.

Here’s the prepared opening for the left scoop. I haven’t yet sanded around the edges. The fuselage comes with a pre-finish from the factory which needs to be removed so that the structural epoxy can bond to it. The section at the top is tapered so that the scoop, which is also tapered, fits nice and tight.

Closeup shot of the left scoop opening after being prepared to accept the factory pre-made scoop.

At this point the preparation for both openings is complete, the structural epoxy with a bit of Flox added has been applied and both scoops are placed into position. I’m using the Clecos to hold each scoop down while the epoxy cures.

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The scoops are being held down by a bunch of clecos while the structural epoxy cures.

Job complete, other than some finishing work to cover up the seams and make it all look nice. The small center scoop gets installed later when the fuselage is flipped upside down for body work on the bottom. There is also finishing work that needs to be done on the two large scoops inside the fuselage. Instead of trying to fight gravity, I’ll do that as well when we’ve flipped the airplane.

IMG 2189

Both scoops are now glued into position. There's still finishing work to be done to blend these into the fuselage.

Now that the fuselage is upside down I can easily finish the strengthening layups around the NACA scoops used for engine cooling and for the cabin vents. the photo below shows the completed layups with peel ply still attached. Because there were pretty huge gaps between the wall of the fuselage and the scoops, I had to add a lot of EZ-Poxy and Micro to fill in those gaps before laying down the fiberglass.

Fuselage -  Engine NACA scoop layups.

Even though these were installed some time ago, I waited to complete the layups used to lock them in place from the inside until the fuselage was flipped. Here they are curing with peel ply.

Fuselage -  Engine NACA scoop layups. 1

The NACA scoop layups are all finished.

There are still some layups that need to be finished on the outside of the scoops along the engine bulkhead. I’ll document that later.

ui© John Trautschold 2018