Did you know a simple leak can lead to a million-dollar repair on a Citation?

One of the most critical inspection items on any Citation is blue-water contamination. This typically starts with pulling the toilet and inspecting the structure underneath for any signs of blue staining. And when I say staining, I mean any hint of blue, especially where two pieces of aluminum meet. Even if a spill was cleaned up, a faint blue tint in a seam is the giveaway.

If you find any sign of a blue-water leak, the next step is to pull the center-aisle floor next to the lav and trace how far the contamination traveled. If it’s there, you keep pulling until you stop finding blue.

In our 10+ years of buying aircraft for clients, we’ve had exactly one deal die in prebuy and it was due to blue water.

During a CJ2+ prebuy, the shop pulled the potty (standard for us) and found evidence of more than just a simple spill. We had them pull the center-aisle floorboard… then the next… and the next… all the way to the cockpit.

I called my client and told him there were only two possibilities:

Enough blue water leaked to run all the way forward, or

It had been sitting long enough to migrate there over time.

Either way, there was no reliable way to assess corrosion risk in the blind butt seam in the aircraft belly.

That repair can run $500,000+ if the wings stay on and $1,000,000+ if they don’t.

So we walked. My client lost the money invested for the prebuy, but he avoided a potentially catastrophic repair. And thankfully, we found him a cleaner, later-model aircraft that ended up being the better deal anyway.

Buyers beware. Blue water is no joke.

Some details:

On my yearly phase 18 inspection, there is a visual inspection of the toilet area for this issue so it is caught early. I suspect other types have similar yearly intervals.

My airplane had a secondary catch basin under the toilet tank. I expect this will be typical of most tank type toilets.

The tank type "flush" toilets are gross. There is only one tank, so the first user gets a clean flush. All subsequent flushes are reusing the now dirty water. The you have to close off the tank and carry it out of the airplane.

I converted my toilet to a dry system. Instead of the bowl and tank, I replaced it with a tub that has a plastic bag liner with pine bedding pellets in it. After the flight when it has been used, just close up the bag and throw it in the trash. The pellets soak up any liquid and deodorize the smell. You can store refill bags in the tank cabinet beside the tub. The pellets also serve as a long term dryer for the closed up cabin and keeps smells down. Another bonus, the weight is reduced by 15 lbs.

I also removed the relief tubes. They produce corrosion, too, are smelly and messy to use. Using TravelJohns is far superior for cockpit use.

I have my Monogram toilet bowl and tank for sale if anybody wants it.

Mike C.

Dry is the way to go!

Just removed mine as part of the interior refurb. Used it once, never again.

That sounds like a crappy situation.

Good thing you were serious about the inspection and not taking the piss.

Is there a number 2 problem to look out for?

I'm pretty sure my life was saved by a relief tube once, though a Travel John would've done just as well. I was ready to pollute the cooler (right after an ice-covered missed approach) when the owner/pilot said, "There's a relief tube."

"What?" I said, "There's a RELIEF TUBE???!!!

It's a convoluted and hilarious story when told by the non-pilot back seat passenger (pilot/owner's brother), whose biggest concern was that in death he would be accompanied by the "smelly dog" in the crate next to him.

OMG

Chip & Mike C agree on something!


RAS

I took mine out completely. GROSS!

I don't think it's the blue water that causes corrosion, I think it's the urine mixed in with the blue water.

But, IMO, they don't belong in a Citation.

That is correct! Most people think it is, but it is actually the urine. Which makes the whole issue a complicated one, as you could easily have urine free blue water contamination and it not be an issue.

But, I’m with you… get rid of that junk!

What approval basis are those of you swapping out the liquid system for a “bag ‘n’ bucket” using? Obviously not STC. Minor mod? 337?

Vac toilets are an option for some jets, but I have no idea if they are for that one. They are greatly superior to an airborne porta-potty.

Mike-I really like your solution, any details or photos of your “tub”?

Minor alteration singed off by an A&P.

In no way does it reach the level of a major alteration. Just because companies get STCs for stupid stuff like window shades and the like doesn't mean the STC was required.

I had a bucket 3D printed to fit the exact shape, had it sealed and painted:

Mike C.

I've attached my STL file for the 3D print. Change the file extension from ".pdf" to ".stl" (forum blocks stl files for some reason).

This was made to fit my Monogram toilet cabinet so no promises it fits what you have. The Monogram toilet was common in small cabin Citations, however.

I also added a small guide at the bottom to keep the bucket centered under the seat.

The pine bedding is available at most farm and pet stores, for example:

https://www.ruralking.com/fine-pine-shavings

That might be a lifetime supply.

Mike C.

Mike,

I love that idea. I’ve simply been putting a bag in the Monogram bowl, and adding some of the same absorbent pads that are used in Travel John’s. The problem with my solution is that the bag doesn’t sit flat, and there is some risk that there could be some splashing as urine hits the bag.

I “think” your toilet is about the same as on my 3+. I tried to download your file, but it shows up as a PDF, and it says the file is corrupted. I’ve never 3D printed anything. Can you tell me if the file you attached is correct? If so, do you have the name of the entity that printed it for you?