SonexBuilders.net

I have had a few inquiries about the 7 gal aux fuel tank that I installed in my Onex. I was planning to fly from Oregon to Oshkosh (and back, with luck) and wanted a bit more range for crossing the wide open places and tall mountains. For CG reasons I figures it had to be as close to the CG as possible and that was against my back. I made a corrugated mock-up of the tank to be sure it would fit. I then made up an aluminum tank with the intention of welding it. All the sides of the tank were bent up from one lone piece leaving seams at the ends and at the top. After welding the top seam I decided to rivet in the end plates using closed end Pop rivets and lots of Pro seal. Threaded aluminum bosses for fuel out and vent were also welded in to the tank end plates. Two large round inspection plates fastened with machine screws into sealed rivnuts were installed in the forward tank wall. A fill tube was made from 2" aluminum tubing and I had to fabricate the tank cap because there's not much room in the Onex cockpit. The tank anchors to the box bean behind the seat back, A Facet pump is installed to transfer fuel from the aux tank to the main tank along with the appropriate ball valves and check valves.

I used the tank several times to and from Oshkosh with no problems or leaks. I would burn off at least half of the main tank then open the valves and pump the aux tank all into the main tank, The only condition to be avoided is to have the aux tank full and only a few gallons in the main tank. That drives the CG close to the aft limit, at least on 362DV.

Vince Homer