Alternate air Intake on a RV 7

Vic from Base Leg Aviation shows the problem with an alternate air setup on an RV-7. Then he shows the correct installation on another RV in the shop.
‪@baselegaviation1614‬
www.baselegaviation.com

[@CuratedPile]

I've got this - horizontally - on my 9A. It's an awful setup. I've had to rework it 3 times in 5 years. It wants to tear out the bottom of my air box and I've had to add a topside plate to reinforce it. The geometry of this is terrible and more often than not the door has worked it's way open, at least partially, whenever I pull my bottom cowling. I'd love to see a completely different design that has guides to allow it to be closed after opening and that you can trust to be closed if the actuator is in a closed position in the cabin.

[@NAUFlion]

Same. That fiberglass bowl needs to be replaced with metal. Not only does the metal ring wear through the bowl but also the filter. And the actuator should be replaced with a rod, anchored to the engine (my 6A plans showed it anchored to the nose gear bracket, which causes severe flex on every engine start). I'm thinking a carbon fiber bowl with molded-in runners for a carbon-fiber shutter would be better, and a metal ring as a rub plate for the filter. Repairing an oil-soaked fiberglass FAB isn't fun or conducive to good workmanship.

[@CuratedPile]

@@NAUFlion A captive shutter would be so much better. And oil-soaked fiberglass is indeed miserable to work with. I like your design, but it would be a significant project to manufacturer. The FAB as a whole was the part of the build that I was least satisfied with, process and outcome.

[@AudioAuthorityCorp]

Factory alternate air design is absolutely the worst piece of engineering on my RV-14. Not at all up to Van's standards. The idea of alternate that requires removing the cowling to restore normal operation is ridiculous.