Firewall Part 2 – Gascolator

Continuing with mounting items to firewall. I had to make a decent-sized doubler (160x120mm) to cover all the holes originally provisioned for the 914 fuel pumps. Instead, the gascolator (fuel/water separator) gets mounted at this location near the bottom of the firewall.

Andair Gascolator
Doubler for gascolator

Meanwhile I’ve also started on all the little cutouts for the firewall “heat shield”, which is not much more than a thin layer of foil with foam backing.

Heat shield fitting

In other news, Rotax issued yet another service bulletin for their fuel pumps: this new one, SB-915i-012, again blames “deviations in the manufacturing process,” which is the same wording they used in the previous 2019 Alert Service Bulletin ASB-915i-011, so now the pumps have to be replaced again! I got in touch with Lockwood Aviation in Florida, and they are running a replacement program. Once they get parts in stock, I simply need to send the whole fuel pump assembly. They will replace the pumps, perform a leak check, and send the unit back to me within 1-2 days.

I’m also working to finish up the right wing, which is all but complete. I came up with a way to mount the landing light lenses to the wing. Rather than use plastic screws that just bite into the polypropylene sheets included with the kit, I designed a simple nutplate to glue down to the lens. These 3D-printed parts have embedded M3 nuts that I insert mid-way during the print.

Captive M3 nuts in this plastic nutplate

Everything looked great until I tried attaching the lens to the wing.. and I found that the pre-drilled holes in the lens don’t line up with the holes in the wing skin (grrr). So, I ordered a sheet of 1/32” polycarbonate and will try to make a new lens, but I will make sure to match-drill to the wing skin.

Holes not lining up, can’t screw in the lens without causing it to deform

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