I'm asking for a friend - literally.

One of our club's planes is an old workhorse used a lot for training. She's got a fuel drain handle in the inspection hatch where one checks the oil. I've never had a problem to place an inspection cup under the cowling and, although looking awkward, to then reach to the inspection hatch and pull the handle. My friend is a lot shorter than me and doesn't reach. Do you have any suggestion of how to go about it? Since I don't have that problem I'm not sure how to go about a solution.

The handbook suggests to let it drain for I believe 4 seconds - which is a lot of fuel, color additive and lead. Although it evaporates quickly it'd be a shame.


2 Answers 2


If they can't reach with a cup, they shouldn't be letting it run onto the ground. If on grass it burns out the grass, and if on asphalt it damages the asphalt (by dissolving the tar component). Plus you can't inspect it.

An airport owner will give you an earful if you're seen running gasoline onto the pavement. If you absolutely must, drain it on gravel or sand.

If I had that problem I'd just take a piece of shoelace cord or string and wrap it around the drain handle so I could pull it up with my hand outside the access hatch.

Or as a Plan B if I can't get a straight pull with a piece of cord, tape the inspection cup to a stick to hold it where it needs to be. A little improvisation goes a long way.

If the fuel in the sample is clean, it should be dumped back into the fuel tank. If it's not clean, on a patch of gravel or into a disposal container if the airport provides one.

  • $\begingroup$ I wouldn't say you can't inspect it if you dump it on asphalt or concrete, it actually can tell you a lot. Fuel evaporates very quickly, after a couple of minutes if there's anything left it's water in the line. Not that I advocate that method. $\endgroup$
    – GdD
    Commented Jun 17, 2022 at 8:40
  • $\begingroup$ You'll see water yes but not particles of crap that could be accumulating on the outlet screen. $\endgroup$
    – John K
    Commented Jun 17, 2022 at 12:33
  • $\begingroup$ Thanks for the suggestion. I was building a handle for the cup but its easier to build a clipable connection to the handle. Used some paper to form and some glas and epoxy to build it, works great. $\endgroup$ Commented Jun 28, 2022 at 9:27

Four seconds is a long time, but if the fuel is still good you can put it back in the tank. It's a bit of an annoyance, yes, but the reason is to make absolutely sure the fuel line is clean. Unless you have a long run-up and taxi the fuel in the line will be hitting your carburetor on your climb-out, which is the worst possible time for your engine to fail due to water ingestion.

Draining the fuel is tricky if you can't reach both the drain and the valve as the valve doesn't spring back on its own. I think it's meant to, but over time loses that capacity and you have to push it back firmly or fuel keeps coming out of the drain. A clever solution I've seen once was putting the cup on the end of a stick. If it was me I'd rig this using bent wire coat hanger, but duct tape would probably work fine too.

  • $\begingroup$ Thanks, I'll have a go bending a wire hanger. Good idea $\endgroup$ Commented Jun 17, 2022 at 14:08

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