Vagabond 11
Member
Is there any information from Van's on the tank sight glass?
Van's Air Force
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Fuel tank sight glass.
- Thread starter Vagabond 11
- Start date
Mark Henderson
Well Known Member
I spoke to them a couple of days ago about a back order. I was told that they still didn't have a permanent fix.
Same here...they said they were testing different types of plastic. I was at the point of finishing my tank and they said, "do not seal it up yet." Hopefully that issue will be resolved soon. Makes you wonder what's in the "blue" one since they said it was certified as an ELSA.
vernhendershott
Well Known Member
I guess this is why we have not seen the firewall forward kit, as Van's would have even more frustrated builders if we were done with everything and still had no gas tank. I am sure glad I do not have to stand in his booth at OSH this week, I would get real tired of all the questions that I could not give good answers to.
I sure hope they find a suitable material or come up with a better tank soon. We are about ready to have a welded tank produced locally if we do not get some good news soon. We will build one fuel tank and use it to certify each of our six RV-12's and then put in the real fuel tank.
Best regards,
Vern
I sure hope they find a suitable material or come up with a better tank soon. We are about ready to have a welded tank produced locally if we do not get some good news soon. We will build one fuel tank and use it to certify each of our six RV-12's and then put in the real fuel tank.
Best regards,
Vern
Geico266
Well Known Member
The only thing I get frustrated by is my impatience.
We are building a new model airplane, to a new FAA & E-LSA standard, using new plug-n-play technology. There are gonna be challenges, problems, mistakes, setbacks, and down right screw ups. That is the nature of the beast for the -12. The engineers are working hard to correct these problems, look ahead to better the processes so in the future there are fewer problems, and improving QA before products are released. I am confident, having met most, if not all of the people at Vans they can (and more imprortantly will) prevale. Just look at the Van's fleet they have produced in the past.
I try to help VA as much as I can from my experience building the -12. When I find a "issue" I e-mail it to them right away, and sometimes call them with it also. (One, or the other is all they need, not both!
) Let's all, as -12 builders take a deep breath and back off just a little and lets the guys at Vans do their jobs. Look in your shop and see what you have built todate, we are CLOSE!
Vagabond 11
Member
Welded tank
Vern, We have four RV12 here in Ocala thats are being built E-AB who could use a welded tank if you deside to have some built. I would think the larger the order, the price will go down.
John
352 245 9954
Vern, We have four RV12 here in Ocala thats are being built E-AB who could use a welded tank if you deside to have some built. I would think the larger the order, the price will go down.
John
352 245 9954
Sight glass solutions
1. Attached is a picture of a cardboard mockup of a RV-12 sight-glass replacement. Instead of using flat glass or plastic, my idea uses two plastic tubes. We have all seen airplanes that use plastic tubes for fuel gauges. So there must be plastic tube available that is gasoline resistant. Even if the plastic tubes become crazed or cloudy or even eventually leak, it is not a problem because the tubes can be replaced from outside of the tank without drilling rivets or messing with Proseal.
2. Do away with the sight-glass altogether and replace it with a second fuel cap. The second fuel cap can be installed on top of the tank inside of the cockpit and would be non-vented. While not as convenient as a sight-glass, it would be relatively easy to remove the cap and look inside of the tank. One disadvantage is that vapors would escape into the cockpit while the cap is off. Another disadvantage is that more baggage room would be lost to the raised gas cap flange, necessary to prevent leakage with a full tank.
Joe
1. Attached is a picture of a cardboard mockup of a RV-12 sight-glass replacement. Instead of using flat glass or plastic, my idea uses two plastic tubes. We have all seen airplanes that use plastic tubes for fuel gauges. So there must be plastic tube available that is gasoline resistant. Even if the plastic tubes become crazed or cloudy or even eventually leak, it is not a problem because the tubes can be replaced from outside of the tank without drilling rivets or messing with Proseal.
2. Do away with the sight-glass altogether and replace it with a second fuel cap. The second fuel cap can be installed on top of the tank inside of the cockpit and would be non-vented. While not as convenient as a sight-glass, it would be relatively easy to remove the cap and look inside of the tank. One disadvantage is that vapors would escape into the cockpit while the cap is off. Another disadvantage is that more baggage room would be lost to the raised gas cap flange, necessary to prevent leakage with a full tank.
Joe
Welded Fuel Tank Option
Vern.
I'm building E-AB as well and would be very interested in a welded tank, particularly if it had a few more gallons of fuel capacity.
Tom
Kentucky Lakes area
270-354-8123
Vern.
I'm building E-AB as well and would be very interested in a welded tank, particularly if it had a few more gallons of fuel capacity.
Tom
Kentucky Lakes area
270-354-8123
MartySantic
Well Known Member
John Bender found a mechanical type gauge that would work very well as a replacement for the RV-12 fuel window. These are the mechanical float type fuel gauges that the boaters use.
http://marineengineparts.com/shopsite_sc/store/html/page378.html
http://marineengineparts.com/shopsite_sc/store/html/page378.html
I think we could just run the tank as is until they find a fix. I have the tank done and installed has been for a long time. It would be much easier to just build a new tank than to modify one that has already been built and installed.Unless they come up with something we can do from the out side of the tank.
If I had the firewall forward harness I would be ready to fire it up for the first time. Engine installed all systems attached and going to paint the cowling .
Brad Stiefvater
Salem SD
If I had the firewall forward harness I would be ready to fire it up for the first time. Engine installed all systems attached and going to paint the cowling .
Brad Stiefvater
Salem SD
smokenjoe50
Active Member
For me they just BO the window part.
I've put this out here before, but I guess some folks missed it. Anyway, the blue RV-12 has the same regular plexiglass window as the red one. The notice for the change was posted after I had the tank, sealed, tested and painted. I conferred with Ken Krueger and we agreed that inasmuch as it took over a year for the site glass to craze, we would let it remain as installed until the final change is in place. At that time, I will make the correction.
Mitch Lock
Van's East Coast Representative
Mitch Lock
Van's East Coast Representative
Sight Glass
Since nobody commented on my previous picture, either it is a bad idea or else I did not explain it well enough. It is a rectangular box mounted INSIDE of the gas tank using existing tank rivet holes. The outside of the tank is not changed much. Looking through the holes, you will see two tubes containing gasoline. Some of the webs between holes would have to be cut out near the top and bottom of the tank to allow working space to replace the plastic tubes if that should ever become necessary. The only disadvantage of tubes (instead of glass) that I can see is that the fittings at each end will take up space. Thus you would not be able to see the level if it was behind the fittings. The big advantage is that the tubes can be replaced from outside of the tank. Comments are welcome, negative or positive.
Joe
Since nobody commented on my previous picture, either it is a bad idea or else I did not explain it well enough. It is a rectangular box mounted INSIDE of the gas tank using existing tank rivet holes. The outside of the tank is not changed much. Looking through the holes, you will see two tubes containing gasoline. Some of the webs between holes would have to be cut out near the top and bottom of the tank to allow working space to replace the plastic tubes if that should ever become necessary. The only disadvantage of tubes (instead of glass) that I can see is that the fittings at each end will take up space. Thus you would not be able to see the level if it was behind the fittings. The big advantage is that the tubes can be replaced from outside of the tank. Comments are welcome, negative or positive.
Joe
Mark Henderson
Well Known Member
Joe, your idea is interesting, but too complicated for what you get. I would rather just rivet a piece of .025 over the holes and be done with it. For visual reference I don't see why a flexible dip stick wouldn't work.
rivet a piece of .025 over the holes
Mark,
I agree with you. Since Vans is intent on having a sight glass and everyone is waiting for a solution, I was trying to help. If I were building an experimental amateur built instead of E-LSA, then I would just as soon not have a sight glass. I was thinking of two fuel gauges, the existing one and an additional capacitance type probe. What are the chances that two fuel gauges using different technologies and reading the same level could both be wrong? The Dynon has inputs for two fuel gauges. And there is a flow meter. A sight glass is not necessary.
Joe
Mark,
I agree with you. Since Vans is intent on having a sight glass and everyone is waiting for a solution, I was trying to help. If I were building an experimental amateur built instead of E-LSA, then I would just as soon not have a sight glass. I was thinking of two fuel gauges, the existing one and an additional capacitance type probe. What are the chances that two fuel gauges using different technologies and reading the same level could both be wrong? The Dynon has inputs for two fuel gauges. And there is a flow meter. A sight glass is not necessary.
Joe
vernhendershott
Well Known Member
Drip stick
If Van's must have a way to check the fuel level manually before flight then the simple way would be to put in a "Drip Stick". They are used on airline aircraft all the time in cases where the fuel quantity has failed in a given tank they just drip the tank to determine the total fuel in the tank. They are very simple devices, they are a small metal tube that slides through a packing to allow you to raise or lower it in the tank. When you have slowly lowered it to the level of the fuel it will start to Drip or run a Small amount of fuel, the stick can be marked with the amount of fuel in the tank or it can be measured and the measurement, say 5" can be looked up on a table which would tell you that you have 6.5 gallons. They would not be hard to make and as they are for a particular tank they could be marked for that tank to save the table issue.
In practice you would just unscrew a cap, pull down the "Drip Stick" until you got fuel and note the quantity in the tank, push the stick back in and screw on the cap.
I think it is all that we would need and we would not have to have all the leaks that will come from all of the holes now in the tank.
Just my thoughts.
Best regards,
Vern
If Van's must have a way to check the fuel level manually before flight then the simple way would be to put in a "Drip Stick". They are used on airline aircraft all the time in cases where the fuel quantity has failed in a given tank they just drip the tank to determine the total fuel in the tank. They are very simple devices, they are a small metal tube that slides through a packing to allow you to raise or lower it in the tank. When you have slowly lowered it to the level of the fuel it will start to Drip or run a Small amount of fuel, the stick can be marked with the amount of fuel in the tank or it can be measured and the measurement, say 5" can be looked up on a table which would tell you that you have 6.5 gallons. They would not be hard to make and as they are for a particular tank they could be marked for that tank to save the table issue.
In practice you would just unscrew a cap, pull down the "Drip Stick" until you got fuel and note the quantity in the tank, push the stick back in and screw on the cap.
I think it is all that we would need and we would not have to have all the leaks that will come from all of the holes now in the tank.
Just my thoughts.
Best regards,
Vern
I want something that I can have quick visual reference to. A quick turn of the head confirms that you still have fuel. With that said, why don't we use what has been in all my other E-LSA planes? A plastic tank. You don't have to build it, you don't have to seal it, and you can see right through it.
Two reasons come to mind right away.
Much heavier.
Much more expensive.
There are other complications also. How is a baffled section (as currently designed into the metal tank) that is needed to assure fuel flow at high angles of attack, to be incorporated into a rotary molded tank?
If you could do that, and then attempted to keep the tank light, it would require other (additional weight) structure around the tank to support it and help it hold its shape (remember this is not just a plastic 5 gallon fuel jug mounted in the baggage compartment).
The metal tank really is the best engineering compromise for the RV-12.
Joe, I must be missing something. If the tubes are inside the tank, how can you replace them from outside the tank?
re: simple
I've been reading this thread with great interest. Now, I'm not even building an RV12, but I might some day. What really strikes me as interesting is the fact that we have all these engineers, some, really high tech at that, and we're having such a hard time engineering a fuel quantity indicator.
I'm not trying to be sarcastic in any way whatsoever and I don't have the answer either. But, with all the really tough things to figure out, it seems like a fuel gauge would be a pretty simple thing to design. Maybe we're over-thinking it.
I haven't seen the instructions or plans. I've looked at the demo plane a couple of time at OSH but not very close and a lot less at the fuel tank. But what's bad with the capacitance sender and a float, since the Dynon has a "gauge" on it?
Marshall Alexander
RV10 N781DM
I've been reading this thread with great interest. Now, I'm not even building an RV12, but I might some day. What really strikes me as interesting is the fact that we have all these engineers, some, really high tech at that, and we're having such a hard time engineering a fuel quantity indicator.
I'm not trying to be sarcastic in any way whatsoever and I don't have the answer either.
But, with all the really tough things to figure out, it seems like a fuel gauge would be a pretty simple thing to design. Maybe we're over-thinking it.I haven't seen the instructions or plans. I've looked at the demo plane a couple of time at OSH but not very close and a lot less at the fuel tank. But what's bad with the capacitance sender and a float, since the Dynon has a "gauge" on it?
Marshall Alexander
RV10 N781DM
Gagarin737
Well Known Member
You can check the fuel-quantity at the Dynon but you also need an second way to see/calculate the fuel in tank(s). Piper use a tab at the 17 gallon point, Diamond uses a system on the drain port. B737 uses drip sticks (don't ask me how I know, I know now that jet fuel stinks ;-) ) and magnetic sticks. Easiest is by sight which is the case at the RV-12. In my opinion the best solution, so wait for a replacement part for the glass (Although the boat tank float types are maybe easier to make).
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Tubes are exposed to air
Joe
The tubes are inside of a 5 sided box. The existing tank side with the 3/8" holes (that you look through) forms the sixth side of the box. No glass is used. You can stick something through the sight holes and touch the tubes. It would be necessary to cut out the webs between some of the sight holes near the top and bottom to allow room to remove clamps and tubes should that ever become necessary. Perhaps Vans will find a glass replacement soon and all of our ideas will not be needed.Joe, I must be missing something. If the tubes are inside the tank, how can you replace them from outside the tank?
Joe
E. D. Eliot
Well Known Member
RV-12 Tank Caper
OK- I now understand that there must be two ways to check the fuel level - seemed to me that one way was enough but I'll bet that somewhere in the FARs lies the regulation. Even with two ways, too many GA aircraft crash land every year due to pilot stupidity (didn't check fuel level or tried to 'stretch it' to a far away airport).
So, regardless of the weight and $ penalties mentioned earlier, I would like to see a plastic/fiberglass, etc., fuel tank in my RV-12. A specially made formed RV-12 tank with clear or milky finish so that I and/or my passenger could guage the level of fuel in the tank both before take off and while airborne. And how about a 24 gallon tank as long as we are 'wishing'?
This is no place to mess around and be # or $ foolish in my opinion. Let's keep it simple and if it costs more to be safe then so be it.
OK- I now understand that there must be two ways to check the fuel level - seemed to me that one way was enough but I'll bet that somewhere in the FARs lies the regulation. Even with two ways, too many GA aircraft crash land every year due to pilot stupidity (didn't check fuel level or tried to 'stretch it' to a far away airport).
So, regardless of the weight and $ penalties mentioned earlier, I would like to see a plastic/fiberglass, etc., fuel tank in my RV-12. A specially made formed RV-12 tank with clear or milky finish so that I and/or my passenger could guage the level of fuel in the tank both before take off and while airborne. And how about a 24 gallon tank as long as we are 'wishing'?
This is no place to mess around and be # or $ foolish in my opinion. Let's keep it simple and if it costs more to be safe then so be it.
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Kyle Boatright
Well Known Member
Isn't the issue still a materials problem. If they found a material you could blow a translucent tank out of, I suspect Van would just use that material to make the window in the standard aluminum tank.
Seems to me like a simple fuel gauge would work just fine. Cut a hole in the tank for the sender, cut a hole in the panel for the gauge, and you're good to go.
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Fuel dipstick as a possible alternative fix?
It is my understanding that the main reason for the fuel view ports is because the fuel level cannot be determined through the filler tube like in most aircraft. So to preflight the fuel level as a cross check on the fuel level gauge, Van used the side tank view ports. So my guess is that while the side ports can be seen in flight (with a limber pilot), the key point is to be able to do the preflight check.
Sooooo: How about a dipstick in the filler pipe. Could be retained in a small tube. It would be sealed because it would enclosed by the fuel cap. No chance a fuel leak from breakage and minimal weight.
Just a thought.
Dave
It is my understanding that the main reason for the fuel view ports is because the fuel level cannot be determined through the filler tube like in most aircraft. So to preflight the fuel level as a cross check on the fuel level gauge, Van used the side tank view ports. So my guess is that while the side ports can be seen in flight (with a limber pilot), the key point is to be able to do the preflight check.
Sooooo: How about a dipstick in the filler pipe. Could be retained in a small tube. It would be sealed because it would enclosed by the fuel cap. No chance a fuel leak from breakage and minimal weight.
Just a thought.
Dave
Mark Henderson
Well Known Member
A couple of days ago an a new Legend Cib came to stay in my hanger for a couple of weeks. It has a slick sight tube to check the fuel level. It is made from an square aluminum housing with the sight tube safely protected. It only requires a fitting at the top and bottom. It looks very well designed and nice looking
