I had a near miss with my Airworld Hawk last week when I took off with the fuel vent bung in place.

The JC 160SE blew a glow plug starting up for a flight in the big scale contest here in Australia. the Temora Invitational Scale Classic. With only a few miniutes to fix it, and its a wing off job in the Hawk, I put a bung on the vent to stop fuel leaking with the model inverted whilst we changed the plug. I simply forgot to remove the bung in the rush. A gear problem wth the model meant a return soon after take off when to my horror I saw the bung still in place. The tank vented via the smoke system but COULD have so easily have caused a flameout. Subsequent flights went perfectly.

So, any bung requires a BIG RED streamer but here's another idea:

If the bung incorporates a Festo one way valve, it will stop fuel drainage via the bung but will allow INWARD venting if you forget to remove the bung. Only a small pressure diff. is required for the valve to open and these fuel pumps can suck really hard. I might even incorporate such a valve in the tank plumbing via a T piece in the vent line.

Worth a thought, might JUST save someones jet ?

Regards,

David Gladwin.