Sumping the tanks

[Stephen Flaherty]

Before buying 9390P I lurked on this website gathering knowledge, so I have felt pretty well prepared for most of the things I’ve encountered in my first 6 months of ownership. The one thing though that surprised me so far is regarding sumping the tanks prior to flight. Of course I had read about the system so I knew about the quirk of a single drain under the belly for all 4 tanks, and I had read that it had to be activated from the cockpit….making it a challenge for a single person to accomplish. But I had not read about an elegant solution to the problem. So, here is my solution, made from about $15 in parts from Home Depot. It fits nicely under the belly, rolls for easy maneuvering and captures the fuel nicely. (photo attached)

Steve

[N3322G]

The most elegant I've seen.

Charles has also made a nice one.

Mine's from Walmart. Low tech 30 qt container.

[Stephen Flaherty]

It might be fun to write a short article for the Flyer showing the different solutions owners have devised for catching the fuel during sumping. If anyone is interested please send me photos of your method. I'll write a short article on sumping and include your photographs.

Steve

[N3322G]

Steve,

search in the upper right corner and I bet you find Charles' photos and FYI here is the process I use.
N3322G FUEL HYGIENE

This is the process we use to sump fuel on our Twin Comanche. It has evolved from the methods we were taught. The results are that the fuel sump screens are remarkably clean at each 50 hour AD inspection – so much so that shops have commented upon their cleanliness. Sumped fuel has been entirely water and debris free for almost two years or more of flying. I should mention that all bladders were replaced in 2009/2010, fuel door seals are fresh and I do my best to keep the fuel caps in good condition. When home, the aircraft is hangared in Texas where the heat eats rubber for lunch.

1. Before the first flight, place 30 gallon sterlite bin bottom under sump drain lines (or something that will catch fuel)
2. Start with selectors on main tanks
3. Sump right main by holding up rear sump drain
4. While holding sump open, change to right aux (notice movement of mechanism in sump area)
5. While holding sump open, change right selector to crossfeed
6. Release sump drain
7. Return selector to right main
8. Sump left main by holding up forward sump drain
9. While holding sump open, change to left aux (notice movement of mechanism in sump area)
10. While holding sump open, change left selector to crossfeed
11. Release sump drain
12. Return selector to left main
a. If fuel in tips - with selector on right aux, turn on master and switch to right tip
b. Sump right tip by holding up rear sump drain
c. Return switch to aux
d. Return selector to right main
e. If fuel in tips - with selector on left aux, turn on master and switch to left tip
f. Sump left tip by holding up forward sump drain
g. Return switch to aux, master off
h. Return selector to left main
13. Check fuel in bin. If debris, individually sump tanks until sumped fuel is clean
a. If fuel in tips, sump right tip external sump on tip
b. If fuel in tips, sump left tip external sump on tip
c. If nacelle tanks have fuel sump at external sump valves both sides
d. If Miller wet wings have fuel, sump at external sump valve on both sides
14. Fly
15. Fuel main and aux tanks (and any other desired tanks)
16. After last flight of day, sump main and aux tanks again.

[SLIMDREDGER]

Pat: I pretty much follow your procedure...draw fuel from all tanks and through the crossfeeds into a container and check for water and crud. I seldom find anything , but if I do I go back and check tank by tank.
I have a plastic dish with a removable top that is approximately 12" x 18" x 3" that I drain into. I can scoot it under the drain tubes with my nose wheel steering handle. It works fine as long as it's not too windy. If it's windy I have to elevate the dish closer to the drain tubes, If the sample is clean I keep my hangar tug fueled with it and do not hesitate to pour it back into the airplane.
When not checking the sumps, I use the dish as a container for minimal tools, a quart of oil, oil fill spout, and a few paper towels,

warm regard, AHP

[Charles Schefer]

Steve, that's a neat design you've come up with. It must be shorter than it looks from the picture else it wouldn't fit under the belly. As far as procedure goes I follow the guidance Pat defined. As far as the fuel sampler / sumping mechanism the solution I came up with that Pat referenced is here -> in this thread.

- Charles

[George Kretschmann]

I copied Charles set up and use it all the time. Pretty handy and get compliments on the setup. Thanks George