Fuel left/right/both on the ground and run-up?

[flyingron]

I do not recall any low wing aircraft I have flown, that had a "both" position in the fuel system.

The two I know about are the Navion and the Ercoupe.

The Navion has one filler and the two wing tanks feed into an accumulator tank down low in the fuselage with rather large hoses. There's only one fuel filler on the right wing and the fuel sender is on the left main tank.

The Ercoupe is a bit more bizarre. It has a fuselage tank with it's own filler and on/off style guage. The wing tanks have their own fillers as well. The left tank flows into the right tank (which has the wing tanks guage) and then there's a valve from the right tank and an engine driven fuel pump to move fuel into the fuselage tank.

 

[flyingron]

My wife and her instructor were ferrying a friends Navion that had just come out of restoration. They found that they could not BUDGE the fuel valve (it had been on MAIN when they departed). Of course this meant they couldn't get to the AUX fuel so they ended up having to land a bit earlier than they expected.

The other issue more than turning the valve is MAKE SURE IT IS ON THE APPROPRIATE SETTING for take off for your aircraft. This can be BOTH, it can be "FULLEST TANK", or int he case of the NAVION it must be the MAIN tank. The supposed justification for the Navion fuel valve ID is almost certainly believed to be a person who took off (or went around) with the AUX tank selected and the engine cut out and failed to respond properly. Unfortunately his wife didn't survive so it became a "fatal accident" in the FAA's eyes. Of course, the real reason was that the new type certificate holder pushed the AD in the hopes of getting some revenue selling Andair (these are sold at Aircraft Spruce) fuel valves to the community at greatly inflated prices. This however backfired when the FAA ACO guys while not being able to not issue the AD, were quite liberal in approving AMOCs. The type society got PMA on their own version of the Andair valve (more nicely done with proper A/N fittings and a mounting similar to the original Navion one where it's recessed into the floor). However, others managed to get one-offs approved and JLOsborne whose fuel valve I had sold me another one that looked just like the one I had except it had a P/N and S/N stamped on it and came with a sheet of ICAs.

 

[kgruber]

Have you built an airplane and crafted your own fuel system to feed the engine from two tanks? What did you do differently from the traditional fuel systems that you claim were full of band aids for lawyers? Educate us.

No. But Bill Barton did. And your Cessna could have had it......till he died.

 

[Stewartb]

My Cessna fuel system works great. I've got lots of hands-on experience with draining it and checking vents/selector/fuel flows, too. The PA-12 I rebuilt from the ground up including a complete change of fuel tanks and associated lines worked great, too. I elected to include fore and aft ports on both tanks and a header tank for each tank, too, all run through a Maule L/R/Both valve. By the way, it, like was provided stock in 1947, had a crossover tube to share venting between the tanks.

 

[Jaybird180]

Now, back to the original thread, in five years in a C172, there were two times I noticed one side (left) fuel gauge going down with the other side (right) staying steady. I switched to the right tank to see what would happen, being ready to switch back immediately if necessary. But the right tank gauge started going down with no noticeable effects. When they became balanced (according to the gauges), I put it on "both" again and all was normal. I was going to have this checked out, but I sold the C-172 and am looking to buy a Bo, which is the reason for my question above).

Normal behavior.

My POH only prohibits operation on L or R during takeoff and landing. My habit is to use Lor R during refueling and on long cruises. It's anooying to see the fuel in one tank go lower, IIRC the other begins to catch up about 1/2 tank, but it's been a long time since I've allowed such a thing.

 

[Ghery]

Normal behavior.

My POH only prohibits operation on L or R during takeoff and landing. My habit is to use Lor R during refueling and on long cruises. It's anooying to see the fuel in one tank go lower, IIRC the other begins to catch up about 1/2 tank, but it's been a long time since I've allowed such a thing.

I think the only time I move the selector on a 172 or 182 from BOTH is when I'm fueling the plane so the crossfeed isn't as fast. Otherwise, put it on BOTH and fly.