What happened to 'Water Drains'
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What happened to 'Water Drains'
Just trying to get an overview on when does your airline do water drains and who does them ?
It used to be at First flight of the Day and then at every refueling thereafter. Nowadays with better quality control of the fuel distribution and tanker to aircraft via manifolds rarther than hand held nozzles it seems to be a lesser risk and therefore not done so often.
This doesn't cater for condensation in the tanks or any leakage of overwing tank caps etc and I miss the security of the ground engineer holding up the drain bottle at the pre flight check stage with a screwdiver with water detecting paste on it and still uncontaminated.
I'm told they do it on a weekly basis during one of the regular checks. How is it with your organisation.
It used to be at First flight of the Day and then at every refueling thereafter. Nowadays with better quality control of the fuel distribution and tanker to aircraft via manifolds rarther than hand held nozzles it seems to be a lesser risk and therefore not done so often.
This doesn't cater for condensation in the tanks or any leakage of overwing tank caps etc and I miss the security of the ground engineer holding up the drain bottle at the pre flight check stage with a screwdiver with water detecting paste on it and still uncontaminated.
I'm told they do it on a weekly basis during one of the regular checks. How is it with your organisation.
Guest
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I think this was really a hangover from the avgas days where there was less bulk fuel control and the engines were less tolerant of water.
The early jet engines did suffer from water particularly with it freezing in filters ( ala RR Dart.)
The control of tank farms and tankers has greatly improved so reduced the likelihood of contamination.
Engine design with efficient Fuel/oil heat exchangers and tank design with scavenging and jet pump systems have all removed the contamination problem from a day to day noperationional point of view.
The main problem now is a fungus (cladisporum)which attacks the metal fuel tanks. This fungus lives on the water both laying in tanks and water that is absorbed into the fuel naturally. This is now treated on maintenance checks with the use of an anti-fungicide ( Biobor)
The early jet engines did suffer from water particularly with it freezing in filters ( ala RR Dart.)
The control of tank farms and tankers has greatly improved so reduced the likelihood of contamination.
Engine design with efficient Fuel/oil heat exchangers and tank design with scavenging and jet pump systems have all removed the contamination problem from a day to day noperationional point of view.
The main problem now is a fungus (cladisporum)which attacks the metal fuel tanks. This fungus lives on the water both laying in tanks and water that is absorbed into the fuel naturally. This is now treated on maintenance checks with the use of an anti-fungicide ( Biobor)
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The theory of water in the fuel tanks as I was taught it a long time ago.
Fuel Storage systems "breathe" In doing so the fuel absorbs moisture from the atmosphere. When an aircraft climbs to high altitude and the air temperature falls, the fuel cools. This causes the moisture in the fuel to precipitate in the aircraft tank. Being heavier than the fuel, the water sinks to the bottom where it gathers at the sump. Draining the sump during the transit or at the end of an overnight stay removes the water from the tank.
I remember the VC10 fuel quantity indication system being particularly badly affected by water in the tanks. Once I was called out to a "fuel discrepency" and asked the engineer who fueled the aircraft if he had done a water drain check. "Yes" he said "and it was absolutely clear." When he had gone I repeated the check and also got a beautifully clear sample. But when I checked the S.G. the hydrometer jumped straight back out again. The sample was pure, crystal-clear water. We drained twenty gallons out of that tank before we got to pure fuel!
If there's fuel in the tank then there's water in there too. Always.
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Through difficulties to the cinema
Fuel Storage systems "breathe" In doing so the fuel absorbs moisture from the atmosphere. When an aircraft climbs to high altitude and the air temperature falls, the fuel cools. This causes the moisture in the fuel to precipitate in the aircraft tank. Being heavier than the fuel, the water sinks to the bottom where it gathers at the sump. Draining the sump during the transit or at the end of an overnight stay removes the water from the tank.
I remember the VC10 fuel quantity indication system being particularly badly affected by water in the tanks. Once I was called out to a "fuel discrepency" and asked the engineer who fueled the aircraft if he had done a water drain check. "Yes" he said "and it was absolutely clear." When he had gone I repeated the check and also got a beautifully clear sample. But when I checked the S.G. the hydrometer jumped straight back out again. The sample was pure, crystal-clear water. We drained twenty gallons out of that tank before we got to pure fuel!
If there's fuel in the tank then there's water in there too. Always.
**********************************
Through difficulties to the cinema
Guest
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Water check are carried out by the refueller prior to each refuel. Fuel tank water drains are carried out at a minimum of each aircraft weekly check, also if the aircraft is on the ground for >4-5 hours. This would obviously change from company to company and by a/c type.
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"please report further"
[This message has been edited by Penn Doff (edited 28 May 2001).]
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"please report further"
[This message has been edited by Penn Doff (edited 28 May 2001).]
In Australia required water checks at the start of the day and after each refuelling are covered by CAO 20.2.
About three years ago, the CAO was ammended to read:
For most Avtur fuelled aircraft the manufacturer recommends a check at the start of the day only, as after pressure refuelling any water in the fuel remains in suspension for too long to make a water paste test effective, and the pellet and syringe tests are too sensitive for aircraft use.
We used to do these drains after each refuelling on the 146, but stopped about three years ago when the CAO changed. Now the drains are done in the morning by engineering as the aircraft is placed on the line.
[This message has been edited by Checkboard (edited 28 May 2001).]
About three years ago, the CAO was ammended to read:
<font face="Verdana, Arial, Helvetica" size="2">5 FUEL SYSTEM INSPECTION
5.1-The operator and pilot in command shall ensure that the following inspections and tests for the presence of water in the fuel system of the aircraft are made:
either:
(i) if
(A) the aircraft manufacturer’s data specifies the manner in which inspections and tests for the presence of water in the aircraft’s fuel system are to be made; and
(B) the data has been approved under regulation 42M of the Civil Aviation Regulations 1988 as part of the aircraft’s system of maintenance;
an inspection and test in accordance with the approved data; or
(ii) in any other case—before the start of each day’s flying, and after each refuelling, with the aircraft standing on a reasonably level surface, drain a small quantity of fuel from each fuel tank into a clear transparent container and check by an approved method for the presence of water.</font>
5.1-The operator and pilot in command shall ensure that the following inspections and tests for the presence of water in the fuel system of the aircraft are made:
either:
(i) if
(A) the aircraft manufacturer’s data specifies the manner in which inspections and tests for the presence of water in the aircraft’s fuel system are to be made; and
(B) the data has been approved under regulation 42M of the Civil Aviation Regulations 1988 as part of the aircraft’s system of maintenance;
an inspection and test in accordance with the approved data; or
(ii) in any other case—before the start of each day’s flying, and after each refuelling, with the aircraft standing on a reasonably level surface, drain a small quantity of fuel from each fuel tank into a clear transparent container and check by an approved method for the presence of water.</font>
We used to do these drains after each refuelling on the 146, but stopped about three years ago when the CAO changed. Now the drains are done in the morning by engineering as the aircraft is placed on the line.
[This message has been edited by Checkboard (edited 28 May 2001).]
