This was an "interesting" trip from Watts Bridge to Gympie. When we took off, we intended to do a 3 leg flight from Watts to Gympie to Teewah and back to Watts. When we took off, there was a smell of fuel (which eventually stopped) and I noticed that the return fuel from the pump appeared to be going UP the vent line rather than down into the tank.
Right from takeoff, I never felt comfortable on this trip. I was sleep deprived and distracted by our new camera. So when we got to Gympie I decided to give the Teewah leg a miss and just go straight back to Watts Bridge. Just as well, as it turned out that I had left the fuel cap off when refuelling in the morning and the opening was pressurising the tank and blowing the return fuel out the vent. When we got back to Watts, we were down to near our reserve fuel which really surprised me, as I didn't realise that much fuel was being vented. On the trip we flew over a very large patch of tiger country and it is quite possible that if we had done the Teewah leg we may have run out of fuel somewhere in the middle of it!
What really surprised me was that we didn't notice anything unusual at Gympie. I didn't notice the fuel cap off on my side of the plane and my wife didn't notice the fuel splashed down her side of the plane. I was fiddling with the new GoPro and my wife was busy filming other planes.
When we landed back at Watts, I was shocked at how much fuel was splashed down the side of the plane.
I guess the moral of the story is: Do a walk around whenever you do a landing and really do those pre-takeoff checklists, also if you're not really on your game, stay on the ground.
Being human, we all make mistakes from time to time. I guess the best we can hope for is that they don't become fatal mistakes. I certainly learned a lot of lessons from this one.