Narrative:

Sumping the fuel tanks on the caravan is tricky. One reason being because the wing is so high. The second reason is because the aircraft designers at cessna came up with possibly the most stupid design ever for a fuel sump. In order to sump it; we have a long (2-3 feet long) plastic tube. At the top of the tube is a point in the shape of a phillips head. You extend the tube up over your head to reach the sump; and use the phillips head to push up on the sump; which has indentations that fit the phillips head. You push up and the fuel is sumped. You can only hope that none of the fuel splashes down on you. But if you accidentally twist the tube to the right or left while you're sumping; you can accidentally pop the sump into the open position and it will stay that way until you are able to twist it back into the locked position. So while sumping the fuel; one of the sumps popped open. I've had this happen before but was able to get it closed again rather quickly. Not this time. The tube filled up and began overflowing. Fuel was now spilling all over the place. I tried and tried to twist the sump to get it to shut which is not easy to do while fuel is falling down all over you. And you're trying to do it with a long tube way over your head. I finally hopped in the aircraft to look in my flight bag (all the while fuel still spilling out). I remembered I had a fuel sump for a regular piston aircraft that has a phillips head on the bottom. I grabbed that; stood on the fuel-soaked slippery tire so I could reach the sump; and was able to force it shut. My clothes were drenched in jet fuel. What was cessna thinking with this design? I changed my clothes and still smelled of fuel for the rest of the night. I talked to other pilots during the night and some of them said they don't even sump the caravan anymore for this reason. It is a health hazard to pilots. It is also a hazard to the environment. I think it is worth the FAA looking into making cessna come up with some type of modification on the sump so you can sump without worrying about it locking open. If they can come up with a modification; why not make an airworthiness directive to fix them all so that we no longer have this hazard?

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Original NASA ASRS Text

Title: A C208 pilot reported the wing fuel tank sump drain can stick open because sump design allows the drain valve to not seat properly when the sump tool is removed and because the wing height makes access difficult.

Narrative: Sumping the fuel tanks on the Caravan is tricky. One reason being because the wing is so high. The second reason is because the aircraft designers at Cessna came up with possibly the most stupid design ever for a fuel sump. In order to sump it; we have a long (2-3 feet long) plastic tube. At the top of the tube is a point in the shape of a Phillips head. You extend the tube up over your head to reach the sump; and use the Phillips head to push up on the sump; which has indentations that fit the Phillips head. You push up and the fuel is sumped. You can only hope that none of the fuel splashes down on you. But if you accidentally twist the tube to the right or left while you're sumping; you can accidentally pop the sump into the open position and it will stay that way until you are able to twist it back into the locked position. So while sumping the fuel; one of the sumps popped open. I've had this happen before but was able to get it closed again rather quickly. Not this time. The tube filled up and began overflowing. Fuel was now spilling all over the place. I tried and tried to twist the sump to get it to shut which is not easy to do while fuel is falling down all over you. And you're trying to do it with a long tube way over your head. I finally hopped in the aircraft to look in my flight bag (all the while fuel still spilling out). I remembered I had a fuel sump for a regular piston aircraft that has a Phillips head on the bottom. I grabbed that; stood on the fuel-soaked slippery tire so I could reach the sump; and was able to force it shut. My clothes were drenched in jet fuel. What was Cessna thinking with this design? I changed my clothes and still smelled of fuel for the rest of the night. I talked to other pilots during the night and some of them said they don't even sump the Caravan anymore for this reason. It is a health hazard to pilots. It is also a hazard to the environment. I think it is worth the FAA looking into making Cessna come up with some type of modification on the sump so you can sump without worrying about it locking open. If they can come up with a modification; why not make an airworthiness directive to fix them all so that we no longer have this hazard?

Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.