Draining fuel tanks

[Mike S]

I need to flush the old gas out of my wing and header tanks. Is this best accomplished by getting the tailwheel propped up and leveling the horizontal stabilizer?
It seems I saw a process like that explained on the forum here, but can't find it now.

[Hank Jarrett]

Re: Draining fuel tanks

If I remember right the wing tanks will drain most when the plane is level and the nose when the nose is as low as you can get it (tail HIGHER than level).

Hank

[Ragwing nut]

Re: Draining fuel tanks

you have drain cocks at the back of the wing tanks so you can empty everything in 3 point

[Hank Jarrett]

Re: Draining fuel tanks

How could I forget those #*%@*&$)* things. They even have those little scalp flags hanging from the pins where I have caught my head on them!

Hank

Just remember you CAN NOT get all the fuel from the main in 3 point.

[Nefj40]

Re: Draining fuel tanks

Yep, no need to get fancy.

you have drain cocks at the back of the wing tanks so you can empty everything in 3 point

[Mark Bowden]

Re: Draining fuel tanks

Please be sure to ground the aircraft for static electricity discharge!!!

Also ground the tank you are draining into and use a tube to get the from the aircraft to the receiver tank. Make sure the tube stays in constant contact with the tank.

The distance from the wing tank to the ground is sufficient to generate enough static to self ignite if drained open in free fall. This activity has burned planes and hangars to the ground.

The tube will also prevent splatter which is another hazard. Don't put the tank on a carpet or mat. Don't wear synthetic clothing, wear cotton. Make sure there is good ventilation.

Be safe, Mark

[M Towsley]

Re: Draining fuel tanks

I thought I read something recently about this, AOPA article from last December: https://www.aopa.org/news-and-media/...cy-up-in-smoke

[Mike S]

Re: Draining fuel tanks

I want to run fresh fuel through the wing tank to main tank line as well, so propping it up to flight attitude should do it.
Thanks for your replies.

[3Dreaming]

Re: Draining fuel tanks

I want to run fresh fuel through the wing tank to main tank line as well, so propping it up to flight attitude should do it.
Thanks for your replies.

You may need a little air pressure to get the fuel to start flowing to the main tank.

[flyguy]

Re: Draining fuel tanks

Just in case someone needs to know this: Hank, et al, the main tank bottom in my BC-12D will drain completely dry with the tail on the ground.

I was pretty sure I had done it that way a few years ago but I checked it when I was at the hangar a little while ago. There is a definite down angle to the front on the bottom of the tank. Are all BC12 tanks that way? I don't know but I am sure this is the original factory tank.
Darryl

[mike lutz]

Re: Draining fuel tanks

I have three airplanes with the original 12 gal. nose tanks, and they will drain completely sitting in three point. Hope this helps.

[Hank Jarrett]

Re: Draining fuel tanks

I need to check this out. I admit I assumed there was unusable fuel with the tail down!

Hank

[Scott]

Re: Draining fuel tanks

Here's a photo without the boot cowl. You can see the shape of the tank is such that there is no unusable fuel from the main tank in the air or on ground.

Wing tanks however need to be in flight attitude for all the fuel to be usable (hence the placard).

https://2.bp.blogspot.com/-mOyvbyeJQ5I/WF8JCCr9ApI/AAAAAAAADa0/R4b-TrmITRYJpln_91RJGbSGsarXeK5XQCLcB/s1600/DSCN5436.JPG

[Ragwing nut]

Re: Draining fuel tanks

I need to check this out. I admit I assumed there was unusable fuel with the tail down!

Hank

There is unusable in the wing tanks in 3 point. But he is asking about draining the fuel, not running them dry.

[Hank Jarrett]

Re: Draining fuel tanks

I have the tank for the 45 in the garage and unless you have some BIG HONKING TIRES up front you guys are right! I hadn't noticed there was THAT MUCH slope to the bottom before.

Hank