We sump airliners every 7 days. Never had anyone report contamination. The worst part of sumping is the 50/50 gamble that the drain will actually close when you withdraw the probe.
Had that happen doing proving runs. Feds weren’t any happier than us to have to spend another night on the road.
There no indication in the description whether the test was done with the tank flat or angled to simulate the wing's dihedral, but that could make a big difference. From the pictures, of the water spread, it looks like not.
I may have missed it, but how long between adding water and sumping?
And getting on end of the wing and rocking the plane helps any water to settle.
bladders - and one of the bladders is fairly new, the other not super old.
I don't know the bladder process but is there any kind of goop they use, maybe not an 'adhesive' but something to help them stick to the walls, or maybe some goop that keeps them wet? I'm reaching, I know....
This is basically where our heads are at. The plane is now offline. Tomorrow we're going to sump - just for funnsies. Then I think tomorrow evening we'll have left tank borescoped and fuel injection cleaned. More to come!
Not super off topic - I've never sumped the jet-a plane I fly. Should I be?
I always sumped the DA40NG.
So when you're in getting the injectors cleaned... ALL of them. It sounds like it is time to flush the tanks and do a borescope. And now days they are a few $$ at any auto parts store, so your mechanic should only charge their time vs any major "borescope" fee.
That's typically a maintenance function.
They did say:
"At the start of the test, 2.5 gallons of fuel was added to the tank making the total fuel 5.5 gallons with no water. From here, a 2 ounce quantity of water was added and permitted to settle to the bottom of the tank"
As I posted my airline only sumps fuel once every 7 days as part of a routine check. We can do this check at the gate, but its usually only on RON (Remain OverNight) ships done late at night.
Most ops at that level have an approved fuel management plan which includes fuel management of the fuel onboard an aircraft. How specific and exacting usually depends on ops type like 135, 121, etc. Some plans restrict where fuel can be purchased, etc. and have some type of audit system included in the plan. For example, a local FBO fuel systems supplies fuel to 3 airlines which required their refuel program to be accepted by all 3 operators and is audited on a regular basis. But errors can still happen, its just few and far between when compared to smaller airport systems which don't fall under a similar requirement.
Yea, but he's going in for the one potentially bad cylinder/injector. I would *hope* the mechanic cleans them all, but if he goes in for ONE cylinder, they could only look at ONE cylinder...
I think that would be a stretch. While I can see an owner remove an injector to look at it and reinstall under prevent mx, the cleaning process requires a testing procedure to determine final serviceability that would be outside the purview of Part 43 prevent mx.
Oops, my bad. Mixed your comment in with something else I had just read.
I do the same.
Yes, the 150/152 tanks are bad that way.
Now, that is an unfortunate and untrue generalization. Most light aircraft tanks are properly shaped to drain water to the sump. Experience matters here.
Rain or snowmelt is a much bigger problem. Some years ago here on POA we did some calculations involving the worst temperature swings we could expect, the amount of water in saturated air (nearly fog) and the volume of the tanks. Even assuming that ALL the water in the air condensed in the tanks and the air was dry when it left, the amount of water was extremely tiny. The same applies to engine crankcases, where combustion gas blowby is a far bigger source of water than atmospheric moisture.
...was thinkin' about them recently.
Find a new mechanic! Mine are checked regularly.
I did this myself. Change out the O rings especially the center small one. 182 and Mooney. Both sat outside. Never water and both were the old killer caps. It’s not hard.
I AM a mechanic. I saw the deteriorated caps.
