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Old 06-21-2022, 06:30 AM
TS Flightlines TS Flightlines is offline
Join Date: Apr 2010
Location: Ridgeland, SC
Posts: 3,110

"I completed the final inspection on my RV-10 last week. (Woohoo). I had a Aerolabs gascolator in the tunnel so no issues there but did have a conversation with the inspector about what would be a sufficient drainable filter.

His concern specifically was that the filter had to have a drain. He further clarified that just putting a T in front of the standard position filter would not serve the purpose, since the filter was on it's side and could accumulate water.

If the filter had been vertical with a T at the bottom for a quick drain, then that would have been ok."

This brings me back to a filter drain for our wing root filters. Ross has an excellent point about a filter that is horizontal, like in our root filter system, and being able to drain the water (if any) from it. So looking at our filters, and the Holley 162-562s that Ross specifies, they are cylinders. So, to satisfy the MD-RA, such a filter would (supposedly) need a 'sump', or a lowered area for a drain, to 'maybe' effectively remove any water from the filter. Putting a vertical filter in a wing root makes the plumbing more complicated, but not impossible. But you still have to have the drain at the lowest point.

The other point was that the filter had to have a drain. Well, in some systems that would be a challenge. Take the RV12IS system for example. The FX375 filter sits above the drain, and the fitting ports on the filter are above the lowest point of the filter by about .75 inch. So, by what Derek's inspector said, this doesnt meet the criteria either.

So---it appears to me that a very special filter with a sump and a drain needs to be made to appease the MDRA. What I dont get is the RV10 and RV14 were not developed for a 'gascolator' nor alot of other experimental aircraft with injected engines. But the kits are sold in Canada and other countries that 'require' a gascolator or a drainable filter. I get it, but you would think a modified fuel system would have been developed by the kit manufacturer for sale to those builders in countries that require them.

Just imagine the shock, horror, and a few very choice words, if you got quite a bit of the kit built, only to find out that it would not get passed because the original fuel system did not meet the MD-RA criteria, and you had to come up with a fuel system mod on your own. Pretty important system to potentially have an ill-designed sytem. Which leads me to ask, who is smarter and right: the Vans engineers or the MD-RA inspectors. I get that the inspectors have alot of power--but to deal with a system like that, I think I would defer to the engineers.
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Tom Swearengen, TS Flightlines LLC, AS Flightlines
Joint Venture with Aircraft Specialty
Teflon Hose Assemblies for Experimentals
Proud Vendor for RV1, Donator to VAF
RV7A Tail Kit Completed, Fuse started-Pay as I go Plan, on hold while we develop new products for RV builders
Ridgeland, SC,
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