Belly sumps in an early 210.

Lowe Approach

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Lowe Approach
Hi all.

I’ve got a 62’ 210-B that I’ve been upgrading and repairing. Overall it’s in great shape, but you don’t know what you don’t know.

on the belly covered by a wilkie button is what appears to be a fuel dump drain. However it’s not a quick drain that I can run a plastic cup into for a fuel sample. It appears to have a threaded cap and is safety wired.

is this not a port for taking a fuel sample? And maybe just to drain the system at the lowest point if necessary? There is one on each side. Maybe people install quick drain plugs here to sample from, I don’t know.

Do you early 210 owners have this and just sample from wings and the strainer? Or maybe there is a mod I need.

thoughts?


Thanks
 
Cessna did as you described on Cardinals. Most people didn’t know the drain existed; until the accumulated water caused problems.

You may find the answer in the Owners Manual. I’ll try to check the SM and see if that gives a clue. Maybe Parts Manual?
 
I checked the service manual but see nothing in the fuel system like that. A lot of airplanes had a drain plug on the bottom of the fuel selector, a plug that is supposed to come out every 200 hours or annually to drain accumulated crud, but I found most of them had never been disturbed since the airplane was built 40+ years before. Found lots of garbage in them. Sometimes had to drain the tanks and remove the selector and dismantle it to the get the plug out. An opportunity to replace the seals in the selector, too.

It might also be something hydraulic if it has an AN cap on it, though the manual doesn't show that either.

The manual: https://mrwebman.com/aviation/cessna/manuals/200_sm_pre65.pdf

Section 2 is the inspection section. Section 5A is the hydraulic landing gear section for the 210B, and section 13 is the fuel system.
 
I googled 1962 Cessna 210B Owners Manual and it shows the plugs in the Fuel System Diagram.

Many Cessnas came with plugs instead of drains that were pulled at Inspections.
wrap a rag around your wrist of course.

IIRC “ If you detect water in the Fuel Strainer you should pull the wing plugs”.

Hmm!!
 
I think this might be it. Item #24: MS20913-1, plug. Which looks like this?

shopping
 
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The OP says there is one of those fittings on each side of the airplane. If his airplane has the header tanks under the floor, those caps or plugs are likely drains for the headers.

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The OP says there is one of those fittings on each side of the airplane. If his airplane has the header tanks under the floor, those caps or plugs are likely drains for the headers.

View attachment 111325
Yep. This is it.
I was just wondering if other early 210 pilots had an stc’d speed drain to check with a fuel cup.

I don’t think my plugs have ever been off so that is immediately in my short list. Although rebuilding the selector valve doesn’t seem like fun at all.

from the diagrams shown on here it looks like those 2 reservoirs are in line before the shut off valve so I imagine draining the wing tanks first is a must. Or I’ll have quite a puddle of low lead to deal with.

any recommendations when I pull these plugs? Towel around the wrist is brilliant thanks. What else should I know? I imagine sediment will collect in the reservoirs so a flexible brush perhaps?
Thanks for all the help.
 
Suggest fly off fuel as much as you wish.

ALWAYS defuel outside and assure proper grounding with CLEAN metal cans.

If they have never been out they may be reluctant to leave. If they are square as
Bell depicted a square socket would be my tool of choice. Not always on hand.

if excessive force is needed ; get someone with skills to do.

After new valves are installed remember you don’t have to fill tank completely
for initial leak check, Just in case!
 
I wouldn't put quick-drains in there. If one of them sticks open or starts leaking (and it will, considering the crud that it might have to drain) there is no way of stopping it short of draining the wing tank above it. There's a good three feet of head there, so plenty of pressure. If it starts leaking, chances are that the airplane's belly will get full of fuel. These things do funny stuff like that even with a hole right below them.

And a gear-up landing with those valves getting smacked on the runway could be a very bad deal.

The same plug was used in the 100-series fuel selector valves, but turning the selector to OFF enabled one to take the plug out safely.
 
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