Dylan Smith wrote in
:

Fortunately, the
cap/dipstick was still where this idiot had left it - on top of the
engine!

Fortunately, I have not done this, but this is one of my greatest
fears..... My way of reducing this is to never completely remove the
dipstick, just enough to see the level and put it right back on. The dip
stick on my Sundowner is not a screw on type, but the type you push it to
"click it" in place and put the pull handle in a flat position.

Whenever possible, I try to top off the oil after a flight, so it gives me
a second oppurtunity (subsequent pre-flight) to catch a mistake should I do
something like you describe above.

You must have a very well balanced prop for the dip stick not to shift in
flight sitting on top of your engine :-)

Allen