Politics and Planes - Negative Ad Campaigns

In surfing around the other LSA plane websites I am beginning to see more than one manufacturer emphasize their gas tanks are in the wings and "not in the fuselage". Presumably this is in reference to the RV-12 that does have the gas tank in the fuselage (to facilitate the removeable wing option).

Although Vans has not really spoken much about the gas tank design I think they have a certain group of potential buyers that are going to take some extra convincing before accepting the fact that a gas tank in the cabin is OK.

My experience with other planes has been mixed. I've flown Cubs, Champs and T'crafts where the tank is basically in your lap just ahead of the instrument panel yet fully exposed to the interior. Some of those planes also had the distinct smell that comes from fuel leaking on the floor board over time. (We are after all talking about 60 year old airplanes).

The 172 that I rent occasionally also had a leaky gas tank recently and you could smell it inside the cabin even though "the fuel tanks are in the wings". So fuel in the wings may not be as secure as the negative adds would lead us to believe.

I don't know if Vans had any plans on changing the gas tank design for production but whatever they do I think a positive marketing campaign is in order to offset the negative ads of the competition. If there are any special safety features added they should be bragged about in the information package about the design.

In the November Kitplanes article they did mention that the fuel pump is hardwired to the master switch and runs all the time. This is a good thing as auto gas can be prone to vapor lock and one of the cures is to pressurize the system.

Has anyone heard any more detail about the gas tank design? Sump location, vents, etc.

Frank

I can't imagine that anybody has heard much beyond what little has been published over the past year. It has been a bit frustrating... but hopefully this new production version will be worth the wait. In regards to the fuel cell specifically - here is what I wrote in a post a while back:

However, I have to say that too many folks are overly worried about the fueltank location on the RV-12. Almost every wreck I have seen (either first hand, or in training documentation) that is survived has a relatively intact cockpit area. The FWF area, landing gear and wings absorb the impact. The tank in the baggage area of the fuselage is probably the most secure location it could be in. Fuel in the wings gives you a greater chance of a large amount of atomized/spraying fuel when a wing is impacted or ripped off. The trade-offs for the RV-12 are in baggage compartment space and C of G issues. I would not make this a make or break checklist item when choosing an aircraft. Don't overestimate the safety of fuel in the wings.

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I hope that there is a flexible connection between the tank and exterior... maybe with some sort of one-way valve. I would also like to see it be a poly tank vs. aluminum. But again... I'm not worried about it... and think that it is just an educational issue. JMHO

Now, if I would just log on one of these days and actually find that the new one is flying...

DJ

Phyrcooler said:

Now, if I would just log on one of these days and actually find that the new one is flying...

DJ

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No kidding. We've had some unseasonably nice weather over the last couple weeks here in Portland. If they haven't gotten it up by now, I would almost say they had an unexpected setback.

--Bill

Fuel Safe

DJ,

your correct in sighting the gas tank may actually be in the best place in the baggage compartment. If you look at the crash worthiness of cars they talk about putting the gas tank in a protected area not subject to penetration or crushing so a lot of gas tanks are place ahead of the rear axle in a "protected" place in the car.

Most aircraft accidents are frontal impact or roll-overs. If the fuselage is crushed enough to get to the tank in the baggage compartment then chances are the occupents didn't make it anyway. I agree with your comment that some kind of rollover check valve would be nice as any plane (RV's included) have the chance of going over on their backs.

There is a race car "fuel cell" provider in Oregon called Fuel Safe. If they can build fuel cells to stay in tact during a race car crash I'm sure one can be designed to stay in tact during a "survivable" airplane crash.

I wouldn't have a clue as to how to design such a gas tank and that is why I'm curious as to what Vans will have to say about it. There is obviously a lot more engineering than just bolting an aluminum tank down in the baggage compartment and running a fuel line from there to the engine.

This and many other features is what intrigues me about the 12. By Vans own admission this airplane is quite a departure from the other RV designs so there were a lot of new engineering challenges to work through.

I'm hoping there is an update in the RVator due out the end of the month.

Frank

I'm not an aero engineer, but to me, the only downside of having the tank in the baggage area is the lack of space for other stuff you might want to travel with. Perhaps the answer is wing lockers for a little extra storage space. This link shows something similar midway down the page.

http://www.zenithair.com/zodiac/xl/cabin-xl.html

I think you are reading too much into the ads. Several, if not most of the LSA's coming infrom the EU have the tank (s) in the fuse. I think the ads you are reading are just telling you where the tank is located. Having the weight nearest to the center line is not a bad thing.

Also, having the option of removing the wings means the tanks would need to be drained every time you removed the wings. Most people who use this feature find that a burden.

Having the tanks in the fuse is not a bad thing.

Safety Marketing

Larry,

I agree that having the gas tank in the fuselage is not a bad thing but the ads that I looked at (Rans, Zenair, Sting Sport and CT) all specifically stated that having fuel in the wings and away from the fuselage is a safety feature. These are not my words but theirs. In fact it seems like the one-upmanship is who can get their fuel the farthest away. I'm assuming someone will come up with tip tanks for an LSA.

Even Cirrus brags about their gas tank in their new LSA as being located "away from the crumple zone" wherever that is (they don't say specifically where it is located)

In the light sport aircraft market where design standards are going to breed similar designs the Marketing people are looking for a way to distinguish their product from others and safety is an emotional button to push.

All I am suggesting is that Vans is going to have to convince some of their potential market that gas tanks in fuselages are ok as others are trying to convince them it is not. Sad to say that Politics and Marketing work on the principle that perception becomes the reality.

Frank

rv-12

picture this. a pilot and pax sitting infront of a 15 gal(?) fuel tank and a 12volt/25amp source of ignition that connect with each other during a hard landing. not necessarily a fatal accident but what becomes one. the design criteria that puts the fuel in tip tanks on the cessna 310 and the lookeed T-33 took this into account. many 1940's planes have header tanks infront of the instrument panel (champ,t-craft,ercoupe etc) so the fuel could be gravity fed to the carb. saftey became an issue in the 50's and the designs changed accordingly. all we are doing is giving the trial lawyers a great oppurtunity with the current design of the rv-12 fuel system. bernie

I don't care where they put the fuel tank. Just get the darn thing flying and kits ready. Who can say at this point what the final design of the fuel system is going to be. At least I have not seen any information on the final verison of the -12. I did all my early training in champs and cubs and the location of the fuel tank did not trouble me at all.

To this day there is a small header tank above the pilot's feet in every brand new super decathlon, as there was in the old one, and the 7KCAB citabrias...it is that tank which has a flop tube for inverted ops.

The LSA-like DA20 has the fuel tank behind the pilots and has yet to catch fire in a crash.

TODR

It's Time

Today is Thursday, January 58th. Was hoping to hear something from Van's by the 55th. Soon, I hope ...