Your gut is correct, the Glasair has a single tip to tip main wing tank with flapper values to keep fuel somewhat balanced across the tank.
Yes, the facet pumps (two in series - main and backup) pump the main wing fuel into the header that then overflows back into the centre of the main tank.
So all fuel is continuously being circulated through the main filter into the header and back again.
There is no fuel tank selection.
During my preflight walk around I always check the header tank is full.
I have a microcontroller I call my ‘CoPilot' managing a series of things onboard.
Two of those functions are:
1. Automatically sense a drop in Fuel Pressure at the engine fuel rail and switch on the backup engine fuel pump.
2. Automatically sense a drop in Fuel Transfer between wing and header and switch on backup transfer pump.
Both these Automatic Backups are checklist tested before flight.
a. Turn OFF main fuel pump, backup activates so engine continues to run, and CoPilot LED changes from Solid to Flashing indicating the backup has been triggered.
While IAS below ~60 Knots(as in we're not flying) by pressing the CoPilot BUTTON, the system is reset/rearmed.
b. Turn OFF main transfer pump…. Same processs as above.
These system tests take about 5 seconds to carry out and are done after startup along with testing computer B and Coils. (Tracy’s EC2)
There is also capacitive senders in the tanks with alarms.
If the header tank level drop below near full, I get an audible voice alarm, and if the transfer flow drops I get an audible voice alarm which means I either have a transfer pump failure or the Wing tank just emptied leaving me on my header tank reserve of 28L
Steve
Thanks guys for all your inputs much appreciated.
Stephen so there is no fuel selection from one tank to the other in your set up.? Or do you select left or right tank with faset pumps for each wingtank ?
152 L seems to me are both wings together as i have also a composite wing..
The header tank flow back to only one wingtank or both ?
Regards Le Roux