Rans S19 and Van's RV-12

I've compared the rans to the vans and cannot figure out why the rv12 won't cruise at 136 mph as the rans does. Same engine, same wing loading, roughly the same height, width and wing span but the rans is 100 lbs heavier. Obviously, I'm not an aeronautical engineer. Any advice? I can't make up my mind between the two on a purchase decision. Thank you

Welcome to VAF!

Jay, welcome to VAF.

Are these speed numbers for the Rans from advertising literature, or from actual flying aircraft you know of??

Vans is usually a bit conservative with their speed numbers.

Sounds like a question for the factory to me.

Good to have you here.

I Haven't looked it up

But I'm pretty sure that Van's advertised an actual top speed of 120 Knots. If I did the math right, 120 K = 138 MPH.

http://www.vansaircraft.com/public/rv12perf.htm

Actually Vans says 135 MPH

I agree that those numbers have so many variables as to be not real useful. I have flown both aircraft and I think they both fly very similarly. I didn't go for a max speed run on either so I can't talk to that. I really love the S-19 and the useful load is the primary reason I am building a RV-12.

Carl

Van's says top speed for the RV-12 is 135 mph. The S-19 claims 136 mph. The 138 mph (120 kts) is the Light Sport aircraft limitation.

I read it as pretty evenly matched.

Dan

So we are arguing about less than 5 minutes on a trip to the $100 hamburger?

I'm glad that you are looking for the best ELSA

Jay, please attempt to get a demo ride in both aircraft and then decide. If you, like me, are going to spend north of 60K, then the comparative costs of getting a demo ride are relatively small. It may be that one or the other is more attractive to you for purely subjective reasons. I did not fly the R-19, I am told that it is a really good airplane. I think that the RV-12 appears to be a little 'stubbier' than the R-19 but after I took a ride in the RV-12 and 'felt' how wonderfully it flew, the decision was pretty well made for me. The RV-12 is an awesome aircraft.

Incidentally, I really like the removable wings - I thought that I would build a trailer and move my RV-12 between my garage and the airport. It seems that almost no one has used this option except to transport their RV-12 to the airport for finishing construction, etc. I am told that I will probably 'park' my RV-12 inside of a hanger that I share with other airplane owners. I have a great deal of respect for those who already are aircraft owners so I give that advice a great deal of credence.

I suggest that you do more home work as suggested above and also post a 'like' question on the R-19 forums. The answer from those on the R-19 forums might be about the same as mine - to paraphrase others here ' build the aircraft that you want to build'.

You might want to check out the various internet forums such as this VAF and see how much help you might get in answering your questions via the internet. The expertise on the VAF (here) is amazingly thorough and experienced.

Final words tonight - there are over 600 tail kits sold by Vans and over 200 flying RV-12s. Not bad. I have no idea how many 'new' ELSAs there in America but I would bet that a very high percentage of them are Van's RV-12s - for very good reasons I think.

Incidentally, you might want to also check out the 'Sling' - is is a really good looking low wing aircraft too. And they also have a kit for sale. Good hunting!!!

The POH gives a top speed on 117kts or 119kts depending on loading. Presumably this is without the optional wheel pants, which seem to add another 3-4 kts. As both aircraft are designed to the same 120kt sea level LSA limit, you wouldn't expect to see much difference, so neither plane is likely to overtake Strega in the circuit at Reno. Although maybe a one-class competition like they have for yachts might be interesting, where the skill and cunning of the pilot is the main differentiator.

Speed not an issue!

RFSchaller said:

So we are arguing about less than 5 minutes on a trip to the $100 hamburger?

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Where's the LIKE button?

RFSchaller said:

So we are arguing about less than 5 minutes on a trip to the $100 hamburger?

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Could make all the difference if they're down to their last few hamburgers

Sent you a PM.

jgm said:

I've compared the rans to the vans and cannot figure out why the rv12 won't cruise at 136 mph as the rans does.

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I'll look forward to you message. Thank you. I have spoken to a rans s19 owner and he cruises at the top speed. I have yet to note that real world cruise speed when reading posts on the 12. I did get the chance to fly right seat in a 12 for 30 minutes. Very impressive but really need left seat time and a good couple of hours to really figure out the power setting speeds. I will be flying 1100 mile trips frequently so the speed is somewhat of an issue for me. I too like the removable wings. My plan would be to always be removing one wing to fit in the hanger next to my Aeronca.

Than you

I regularly get 122 kts with the wheel pants and 5.0 gph. I am pitched so that I generally have to throttle back just a bit to avoid hitting the rpm limit at moderate altitude - say 6000 ft. I think that the prop pitch is the biggest variable in any 12's cruise speed and other performance. Tiny changes make a significant difference and the somewhat poor repeatability of the prop adjustment takes careful effort. My engine is still breaking in as well. No doubt it is an honest 120 kt plane.

Has anyone installed an electrically pitched prop? For Post-inspection ELSA if the switch was not accessible from the cockpit (like maybe through the oil door) it could still be considered "ground adjustable." Maybe? If so, Set for climb for lifting off your short home strip, stop to top off for fuel and set for cruise. Of course no one would hide a parallel switch in the cockpit...

I doubt the difference in real world cruise is 5mph...so lets crunch the numbers.

1100 mile trip is realistically 2 fuel stop territory. So equal legs would be 367miles.

367miles/136mph is 2.7hrs
367miles/130mph is 2.8hrs

Difference is only 6 minutes per leg. Or less than 20 minutes on a 9hr flight time day.

Also need to factor in the build time, if the Rans build takes 100hrs longer(and it will). You could make your 1100 mile trip, 10 times.

I would offer one other difference in building between the two.. or actually two differences. I bought the plans for the S-19 after visting RANS and flying the plane and touring the factory. In looking at their plans, they are not quite as clear to a first time builder as Vans. Now of course I have built 75% of the RV-12 from Vans plans so I guess my perspective on that may be slanted. It is a difference though.

The second difference to consider is the construction technique. The S-19 is a true pulled rivet aircraft. All the rivets are pulled. The RV-12 is advertised as mostly pulled rivets. I think this is not completely true. I guess it depends on how one defines mostly. There are quite a few solid rivets of all sizes in the build of the RV-12. This is not a huge deal but it is something to consider. With that said some of the larger metal pieces require bending and forming in the case of the S-19. So it is truly a trade.

Carl

The 80lb empty weight difference would be the decision maker for me, so I would go RV12. The useful load on LSA's is skinny enough as it is, I would be looking for all I could get.

Tim

DanBaier said:

Van's says top speed for the RV-12 is 135 mph. The S-19 claims 136 mph. The 138 mph (120 kts) is the Light Sport aircraft limitation.

I read it as pretty evenly matched.

Dan

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I know of an RV-12 that top speed is 142 MPH ...... allegedly. But who flies WOT? Pull back the throttle to cruise around 125 - 135 and enjoy the day. What is the hurry? Enjoy burning only 3.5 - 4.5 gph.

The owner has been told the the FAA will send armed federal agents repelling out of black helos, but he is still flying so evidently their radar guns are not up and running in the area. .

Bill_H said:

Has anyone installed an electrically pitched prop? For Post-inspection ELSA if the switch was not accessible from the cockpit (like maybe through the oil door) it could still be considered "ground adjustable." Maybe? If so, Set for climb for lifting off your short home strip, stop to top off for fuel and set for cruise. Of course no one would hide a parallel switch in the cockpit...

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No need for all that Bill, just put the switch INSIDE the cockpit with a placard stating that it must not be adjusted while in flight. When you are sure nobody is looking, fiddle with the switch.