DonFromTX

DonFromTX

Well Known Member
Just curious, have you found any difference in wing heaviness difference with and without a passenger?
 
Don, not much difference at all. Curious - with your wing tank setup do you have a Left and Right fuel selector. Both position? Seems as though balance could become critical with the fuel so far out in the wings.
 
No right or left, the four wing tanks all gravity feed into a small center tank (dihedral you know) which feeds the engine and has the return line.
We do not have any baffles in the wing tanks however, some concern about that. There are only two planes flying with this setup so far, the prototype and Dick Gossen whose first flight was mentioned above, so it is still a bit of a work in progress..
 
Are there plans underway for anyone to do a spin recovery test series in an RV-12 modified with full span wing tanks?
 
DonFromTX said:
No right or left, the four wing tanks all gravity feed into a small center tank (dihedral you know) which feeds the engine and has the return line.
We do not have any baffles in the wing tanks however, some concern about that. There are only two planes flying with this setup so far, the prototype and Dick Gossen whose first flight was mentioned above, so it is still a bit of a work in progress..
Click to expand...

Is there anything to prevent back flow from one side to the other?
 
BigJohn said:
Is there anything to prevent back flow from one side to the other?
Click to expand...
Only a small 1/4 id tube from one wing to the other, we have discussed check valves to prevent backflow, but earlier tests seem to indicate it is not necessary. It would take a while for 10 gallons to flow from one wing thru such a small tube to the other. It can however flow to the small fuselage tank and overboard thru its vent if it wanted bad enough and the low wing got full of fuel. My Ercoupe used about an identical setup, and crossflow between the wing tanks never seemed to be a problem to my knowledge.
Keep in mind this is an experiment of a fuel system, things may change as we get smarter or deader.
 
On the other hand, Scott, we are prohibited from spinning by the POH even in the approved configuration. --- just sayin'.😁
 
RFSchaller said:
On the other hand, Scott, we are prohibited from spinning by the POH even in the approved configuration. --- just sayin'.😁
Click to expand...


Intentional spins are are prohibited in the POH, but youtube is full of videos showing that the RV-12 has no unusual recovery characteristics.

Spins don't always happen on purpose. In fact the ones that kill people are usually entered inadvertently.

It's good to know that it will actually recover from one if you ever inadvertently entered one.......
 
Circular problem

I'm struggling to follow how this gets resolved. POH prohibits intentional spins, but the builder of an experimental aircraft can apparently modify the aircraft to the point where spin testing with the new (tank) configuration is a legitimate question. Scott does regularly point out that Van's testing was done on the current configuration and when builders make changes (even just the type of rivets used on the wing walk area if I recall) one cannot just assume the aircraft would meet the original test standards.

Would the FAA be comfortable (or even encourage) a builder "intentionally" spinning a modified experimental RV-12 as part of a controlled test? If that's allowable, then next debate will be who's qualified & what safety procedures should be used.

If not, then the unknown impact on spin recovery with this tank mod will always be hanging out there.
 
Clarification....

An E-LSA RV-12 is an experimental aircraft to the same degree as any Experimental Amateur Built (E-AB) with one exception... It must be operating within the performance requirements stipulated for Light Sport Aircraft, so any modification or operation must not take it outside of those boundaries.

In an effort to improve the level of safety, when it is first built, to qualify as an E-LSA, the airplane must be built as an exact copy of an aircraft that previously met the consensus standard requirements of an S-LSA.
After that, it is just another experimental aircraft (other than meeting the performance requirements as described above).

In a further effort to improve safety, The FAA requires that any documentation that was part of the certification of the S-LSA example, also be supplied with the E-LSA kit. It is useful for the E-LSA owner, but it is not binding (other than the use of the inspection check list during the annual condition inspection). There are no FAR's that require an E-LSA RV-12 owner to comply with the "Intentional Spins Prohibited" in the POH. That is only binding for an S-LSA (it must be operated within all of the requirements stipulated by the manufacturer).
 
You must log in or register to reply here.