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.

I always put a bung in my jets vent pipe for travelling to avoid any spills. I attach one of these red "remove before flight" cloth labels. Easy to see.

David.
I've done the same miss 2 or 3 times. All on my Euro when the glow plug failed before a flight. All ended with flameouts after 2-3 minutes in the air. Luckily with a happy ending
The M160 has a hunger for plugs, so the solution for me was to add a "remove b4 flight" tag on the bung as you said + that I now always check that the glow plug works after each fligt by initiating a start after cooldown (you get a message on the Gaspar gsu if it's broke). Better to find out after a flight than just when you are about to fly standing in que at the flight line.

Peter,

I've thought about that in the past bus reasoned that it would interfere with the venting when I'm filling the tanks since I just use a piece of brass tubing protruding from the side of the fuselage . I guess if the the Festo fully opened when the tank is attached it could work...

Marc

..check list is one trick!
the other is the "remove before flite"[8D]
http://dreamworksrc.com/catalog/prod...roducts_id=197

David, have done this myself 2 times. Luckly I see my tank starting to look like a balloon and reach over and pull it. gonna put some lettering on the top of the fuse and than mabey will catch it from now on. At least I know my tank is a tough one!!!!

If I understand your idea, wouldn't that defeat a taxi tank?

George

Hi David

Glad it ended happily. Most UK events require you to use a taxi tank for filling and starting, therefore that alone will stop this from happening.

Duncan

David,

Using a Taxi Tank when filling and starting will prevent this from happening to you again and also allow you to conserve your on board fuel supply for the actual flight.

I'm glad that nothing happened to your plane.

Bob

Never used a taxi tank but the incident has certainly concentrated my mind., came so close to a flameout with a jet heavy with full fuel and smoke fluid ! Perhaps I'd better couple up that BVM overflow tank (I always connect it during refuel to collect spill) during ALL starts, or use a checklist AND use a long red streamer on ALL bungs !

Regards,

David.

Two types of folks in the world, Dave: Those who have, and those who will ! :-)

I knew damn well I would definitely make this mistake myself, and attached a flag to the vent beginning with my first jet build.

I find it impossible to miss that flag hanging in the breeze during taxi out, but guess what? I found that working right over the top of the jet, it's still possible when one's head is "up and locked", to miss the plug during fueling. I was lucky that I didn't blow a line off before I figured out why my pump was running so slowly. LOL

The flag idea, combined with the taxi tank "ritual", helps for me. I once took off with the vent plug installed before I began using a taxi tank and before using a flag, after having a last minute issue that required a delayed takeoff and a small maintenance action. Saw it on the liftoff - a short pattern and overweight landing made, and a lesson learned the easy way for me thanks to luck. It's that sort of disruption to routine that opens the door. The challenge with using a printed checklist (for me) is multi-layered - first, it's a separate piece of paper that requires a place, and second, the chance of misplacing it in the typical RC outdoor environment (winds blow it away, etc.), and finally the temptation to make an obnoxiously long checklist in the first place that covers the bathroom break, call to the wife, what have you. Maybe a better solution would be to memorize a short mnemonic checklist like glider pilots use in small single pilot cockpits of simple aircraft - RUFSTAL for example for the landing checklist - Radio set and initial call made, Undercarriage down and locked, Flaps set, Speedbrake checked and set... and so on. There is a separate one for takeoff. We really only need one for takeoff but it would not hurt to make a simple one up for landing. That way it stays short and sweet and there is no overly complicated list that is a setup for misuse or confusion.

Just an idea and example thrown out, etc.. I'll just make one up on the fly to see if it could work for some guys - "RUFFFSTAL" - (R) Radio (Proper model selected and battery checked for both TX and RX before flight), (U) Undercarriage (pressurized and swung, brakes charged and checked), (F) Flight Controls (Physical check and function, right throws, rates, direction...), (F) Fuel system (full tank, no bubbles, no PLUGS), (F) Fire awareness (engine start, extinguishers, spotter plan to use the extinguisher), (S) Situation Awareness (Who's flying where, what station box to take, who's your spotter, are the conditions still good to fly, review flight plan / desired actions), (T) Trims and flight modes set for takeoff, (A) Announce runway/takeoff, (L) Look (before entering runway, before turning into anyone in flight, before making a low pass, etc.). As long as you remember the RUFFFSTAL you'll remember your items and you can do the checklist while in motion and with hands full. The "RUFFFSTAL" is not important, just that a short and sweet custom checklist is come up with to hit the big points, and regularly practiced. Maybe just attach a very small piece of paper with your letters on it to the TX and look at it if you get short on brain capacity, and you'll pick up from there.

I have always used an overflow tank during filling. One time i set my gas can down on top of the overflow tank fill line, pinched it and split a tank open during the fill...[:@]. That time i was doing too much talking while setting up for a flight and not paying attention to my jet. Anything is possible as i have seen someone take off with the overflow tank still connected and sitting on the wing.[:-]
V..

Hi David,
This is from the KS manual. The anti-spill tank works 100% to keep JETA1 from your car. The fuel system depicted also keeps overflow from getting onto pit area when refueling. Its fuel and forget and enviromentaly sound.
BRG
Andre