planes with the aux tank

[zzoldtown]

I've seen a few ads for planes with the aux tank. Does it hide under the back seat? I'm guessing it adds about an hour's worth of fuel and I can't imagine it's a very light modification.

[Jim]

Hi,

The tank holds 7? gallons and was an option offered as the planes were built. When you run fuel out of the right the aux tank can be pumped up into the right tank. So, it's not really difficult to install the system as Piper accommodated and paper work should also be EZ.

[akflyer]

I've seen a few ads for planes with the aux tank. Does it hide under the back seat? I'm guessing it adds about an hour's worth of fuel and I can't imagine it's a very light modification.

I have a couple of the tanks, they really don't weigh much, probably on par or real close to the weight of the fuel jugs I carry. I only removed them because it takes up cargo space when I have the back seat out. Been more than one trip I have done that I wish I could have just flipped the switch to put the gas into the wing tank instead of finding a place to land and dumping it in from fuel bags or jugs.

[Steve Pierce]

There are some pictures here.

https://www.shortwingpipers.org/foru...el-Valve/page5

[grbamford]

I have the aux under my aft see. I believe it's a 9 gal capacity. System is pretty fool proof.

[Glen Geller]

The details of the aux tank installation are in the PA22 150-160 Owners Manual, page 19 or sheet 11 of this fuzzy pdf:
https://www.ninelima.org/poh/Piper/P...iPacer-POH.pdf

The tank holds 8 gallons, the whole shebang is probably 10~12 lbs.
I have one in my 1955 PA22-150, and unless I know I'm going to be taking two or three passengers, I keep it full - Tri-Pacers fly best with a bit of aft loading.
There's a neat pull-push knob on the panel that opens a hoof valve like the PA22 parking brake and simultaneously activates an electric fuel pump under the right front seat.
It takes ~20 minutes to pump all 8 gallons from the aux tank to the (less than half full) right main tank in level flight.
There is a sump without a strainer and a drain valve included with the aux tank plumbing, to check for fuel contamination before flight, just like the mains.

I think the hardest part of adding the system to an existing covered plane would be the piping from the pump into the right main tank.
The aux tank was introduced in 1955, the first year of the 150hp planes, so it's unclear if it would be legal to install in a pre-1955, 135hp or 125hp Tri-Pacer, or a PA20, since it was never offered on those.

GG

[grbamford]

I had a heart stopper learning moment with my aux tank last summer. Before I moved into a single hangar, I was at a group home for airplanes needing a room. The FBO would move our planes in and out when another pilot wanted to fly. The day I was moving my plane to its new home, I went out and did my pre-flight, got in and turned the battery on. Before I knew it, fuel was streaming out of the right wing. Holy crap! Got out, checked my fuel caps, lines and drain valves that I could get too. Nothing unusual. Got in, did it again (I'm a slow learner some days) and started gushing fuel again. Swept the cockpit and found that the push/pull knob was pulled out. Pushed it in and no more fuel splashing about. Found out that the young man who brought my plane out was an aspiring pilot and had sat in my seat, played pilot and thought my it was my carb heat valve. Bad on me for not checking that before I hit the battery.

[smcnutt]

Someone on here (might have been Gilbert) suggested installing a check valve in the plumbing. Otherwise there's only a o-ring failure keeping the 18gal right tank from flowing down into the 9gal auxiliary tank and overflowing all over the hangar.