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-   -   Rans S19 and Van's RV-12 (https://vansairforce.net/community/showthread.php?t=96076)

MacPara 02-05-2013 09:04 AM

Sent you a PM.

Quote:

Originally Posted by jgm (Post 741202)
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.


jgm 02-05-2013 05:47 PM

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

Bill_H 02-05-2013 06:26 PM

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...

hydroguy2 02-05-2013 06:28 PM

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.

newamiga 02-05-2013 09:27 PM

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

tjo 02-05-2013 10:38 PM

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

Geico266 02-06-2013 06:36 AM

Quote:

Originally Posted by DanBaier (Post 741222)
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

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. :D. ;)

DonFromTX 02-06-2013 07:27 AM

Quote:

Originally Posted by Bill_H (Post 741518)

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...

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.


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