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RV-12 Pants

Yes

Yes Scott. There can be no ELSA without a supporting SLSA. Van's has included all of these options on the certified SLSA so yes you can include them in yours if you wish. Their name is on you dataplate as the builder...they have an interest in providing you a plane that stays within the guidlines.
 
Cool

Peterk said:
Yes Scott. There can be no ELSA without a supporting SLSA. Van's has included all of these options on the certified SLSA so yes you can include them in yours if you wish. Their name is on you dataplate as the builder...they have an interest in providing you a plane that stays within the guidlines.
Click to expand...

That is great, thanks.
This should be a great plane to build and fly.
 
Currently an RV-12 with a correctly pitched propeller has a max cruise speed at maximum continuous power (this requires flying at an altitude that allows the appropriate manifold pressure and 5500 RPM as Peter was referring too), of about 116 knots. The optional RV-12 wheel fairings and nose gear leg fairing appear to increase the max. cruise speed somewhere between 3 - 4 kts. This puts an RV-12 with the optional fairings at right near the 120 kt limit.
The complete fairing installation weighs just a bit over 8 lbs (with no paint).

If I am doing my math correctly, that makes an RV-12 built with all available options and a moderate paint job, at an empty weight of about 745 lbs. Right about 5 lbs below the original design goal of 750 lbs.
 
Great speed and better looks

So what would you estimate max cruise (TAS) to be at 8500 ft. with the wheel pants?
What fuel burn rate?

I would expect the nose wheel fairing to add 1-2 knots as well.
Van's said the gear legs on the RV-10 (which are round on all three) add more drag than the wheels themselves which means you get more speed from the gear leg fairings than the wheel pants on the -10.
 
ScottSchmidt said:
So what would you estimate max cruise (TAS) to be at 8500 ft. with the wheel pants?
What fuel burn rate?

I would expect the nose wheel fairing to add 1-2 knots as well.
Van's said the gear legs on the RV-10 (which are round on all three) add more drag than the wheels themselves which means you get more speed from the gear leg fairings than the wheel pants on the -10.
Click to expand...

Max cruise at 8500 " and 5500 RPM (max continuous RPM) and full throttle, should be right near the 120 kt limit. Rotax rates the max cruise power fuel flow to be about 5.5 GPH. The 4 Kt speed increase I mentioned is with the nose leg fairing and all wheel fairings. Keep in mind that an airplane in the speed range of the RV-12 (130 - 135 MPH) gets a much less increase in speed from the installation of wheel fairings compared to the other RV models with speeds that are 55+ MPH faster to start with (the change in parasitic drag is non linear as the speed increases)
What you mentioned about the gear leg drag is correct, but less so with a nose gear leg than the mains because of the shallow angle relationship to the relative wind. At this shallow angle, the cross section of the leg against the relative wind is somewhat airfoil shaped. On an airplane the speed of the RV-12 it will probably be difficult to measure the speed difference comparing with and without the nose leg fairing, but one was developed because there obviously is some drag from it. The main gear legs are probably not much so it wasn't worth the cost / weight And we can't have RV-12's going too fast :D )
 
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