Water checks procedures

[stadedelafougere]

Hi everyone.

I am currently working on a project aimed at reducing the operationnal costs induced by the presence of water in the fuel tanks of an aircraft.

Do you guys have an idea of the period at which water checks are carried out (every other day, every week...?) and how long it takes?

I guess it depends on the aircraft and the routes it is flying. If possible could you give me example?

Besides, I couldn't get my hand on AMMs where I would surely find this kind of information; any idea where I could find these data?

Regards,

[NutLoose]

well light stuff such as you have at Cranfield, 152's, pipers etc it is part of the pilots Preflight walkround to check for water prior to flight.

[Engineer_aus]

Big stuff, supposed to be after every refuel, or start of the days flying and end of days flying.

[mitzy69]

fuel tank water checks need to be completed after every refuel.
but it needs to be done after the fuel has settled after refuelling or the aircraft has remained stationary for 0ne hour
therefore cannot be completed on transits stops after fuel top ups, but left till the daily check at night.
OK on B777 as just 3 tanks but B747 has 8 tanks.
most A/C these days have pipes that suck fuel from the lowest point in tank and discharge it to the inlet for the main pumps, so water constantly scavenged from the bottom of tank, and water checks do not yield the gallons of water that B707 did.
fuel water checks were a bonus for the mechcanics in third world countries, as it was used for cooking, and a oil drum of fuel would disappear into the jungle after aeroplane choxs off.

[winglit]

In our company we do fuel water drains on our A330 every weekly check. A/C is pre-fuelled with about 10T of "warm" fuel and left to stand for six hours to let the ice melt.

Then the tanks are drained. We get gallons of water out of them.

Other than the weekly check the A/C never cools down or the ice in the tanks melt, max 2hr transits. If it wasn't for the fact we needed 6hrs ground time for it to stand, OPs would continue to fly it. We use this valuable ground time to catch up on maintenance and try to clear a few B's.

[Mr @ Spotty M]

You will find that a fair number of airliners from Boeing and Airbus do not require water checks on a daily basis.
Most airlines require that a sample of the fuel being uplifted is checked at the fuel bowser for water.
The aircraft now tend to have jet fuel pumps which can pick up the water unlike the old types. The A330 has a requirement to have a water drain because l understand this type of pump is not fitted, hear that this is a future mod.
Some a/c have a requirement for a water check on a weekly basis but it is the airline that introduce this and not the manufacture.
You can not do a water drain after you refuel because it will be of no use, you require 3 or more hours for the water to settle to its lowest point in the sump of the tank.
Hope this is of help.

[spannerhead]

I was thinking the same Spotty. Water drains after a refuel? Never in my experience. It does make me wonder sometimes about the calibre of posters on this and other sites!

[spannersatcx]

Every time we refuel we do a check of the bowser to ensure that we have put fuel on rather than water, a quick and simple test. Once a week we do a drain of the a/c fuel tanks, to remove any water collected at the bottom of the tanks.

[winglit]

We also do water contamination checks during refueling. The syringe with the tablet on the end. Once tested, spit on it and check that it turns blue. Then you know that your tester was good and your fuel is water free.

I am asked by the crew to perform this check as part of my ETOPS transit check. But I always ask the same question, "And if I find any?" I don't know what I am supposed to do if I find water contaminated fuel during refuel? There are no empty bowers to do a defuel and all the fuel at my airport comes from the same place.

A330s accumulate a lot of water in the wings purely from condensation. In fact most long haul A/C that fly to hot and humid destinations will.

[spannersatKL]

Spannerhead....clearly never done a QANTAS B747-200.....the FE wanted to see all the samples AFTER fuelling from ALL tanks.....

[Fuel Boy]

As a fueler I can say that we do a check before we start our daily fuellings, and then we check the fuel for water after every fuelling sometimes it's checked whilst fuelling..:ok:

On the water front we were tasked to De-fuel a 330 (a few years back). Before we can do this we require a water free sample before starting, on this defuel almost 4 220 ltr drums were filled before we got our clean sample :eek:

The only time you find water in fuel is in A/C tanks, and in some cases enough fuel can give poor FQI readings.

Can't say that I've ever seen an engineer do a daily check ;)

Fuel Boy

[stadedelafougere]

Than you very much all of you for your answers.

As it may ppear, companies have different practices regarding these procedures. And the different technologies implements on different aircraft make it quite difficult for me to get a global picture of the cost of this problem for the airline industry.

Do you guys frequently have to deal with corrosion induced by the presence of water in the tanks or is this problem really marginal and left to certain companies?

[mono]

SpannerKL

If the FE wanted to see water checks from all tanks right after a re-fuel he was wasting his and your time. The fuel going into an aircraft is almost always water free. In case it's not the fuel is checked before and during fueling. It's a bit late checking it after the thing is full of fuel!!

As has been said before the majority of water in fuel is as a result of condensation not dodgy fuel.

[IFIX]

It is not as much the presence of water that will cause corrosion inside a fuel tank.
Any water left for sufficient amounts of time tend to atract fungus.
This fungus actually feeds on fuel but requires water to multiply.
The waste product of this fungus is about as acidic as car battery acid!!

We do fuel drains on our MD-11's every weekly, at most it yields half a quart of water from the entire a/c.

[stankou]

We operate on Beech in a tropical island, high temp and lot of moisture, very nice for fongus growth. We drain our A/C daily BEFORE refueling, we request a water test from fuel supplier every first refueling of the day, and we add Biobor every 3 month.

[winglit]

Here's a very good wiki article about cladosporium resinae, more commonly known as Gladys.
Microbial corrosion - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Microbial_corrosion)