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RV-12 200 hour club 11-2010

JBPILOT

Well Known Member
Super day in Iowa for early November. Turned over 200 on the way back from a trip to the Mississippi River.

John Bender

RV-12NEIOWA11-2010100_1687.jpg
 
Congrats! After 200 hours, what do you think? Any expectations not met? Anything you wish was different? Any unexpected surprises? It would be cool to hear a long-term review.

--Bill
 
Hey Bill - - -

Thanks first. I have only a couple things that I was less than thrilled with on the RV-12. The first is the gas tank, which I solved by closing the window and installing a Moeller Marine fuel gauge in the top. The other is the cabin heating for cold climates, which I solved with my "Heater Damper Door" system.

The plane is everything as advertised, which is great. It flies great. It is as easy to get in and out of as any model I have been around. Visibility is the best ! ( as advertised ) !

I have all the mods done I wanted, and the plane is truely a great plane. It is light, and as such is is not a perfect ride in rough weather, but that is understood up front. I think the RV-12 is as fine a plane as you can purchase for the money ( good value ). That about says it all.

John Bender
Iowa, USA
 
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Hey Dave - -

At the speed I was going, it was showing about 4.9 GPH of high test auto fuel most of the time. I would guess I was at about 75 - 80% throttle. The picture shows 112 knots indicated. I was able to get 126 knots WOT earlier that day. At WOT, it shows about 5.5 GPH.

John Bender
 
At the speed I was going, it was showing about 4.9 GPH of high test auto fuel most of the time. I would guess I was at about 75 - 80% throttle. The picture shows 112 knots indicated. I was able to get 126 knots WOT earlier that day. At WOT, it shows about 5.5 GPH.

John Bender

Uhh, I hope you are EAB (or at sufficient altitude/atmospheric conditions), because otherwise you just posted on a public forum that your plane is not airworthy anymore.

"A maximum airspeed in level flight with maximum continuous power (VH) of not more than 120 knots CAS under standard atmospheric conditions at sea level."
http://www.aopa.org/whatsnew/regulatory/regsport.html
 
GLAD YOU ASKED !

It is misunderstood - - - - a bunch ! The spec's you quoted are correct. YOU MUST understand, they are at MAX GROSS and at SEA LEVEL. If lighter, and higher, it will go beyond 120 knots. IT WILL NOT if at gross and as near to sea level as you can get for your area. Very happy you asked that question. Seems to be very much misunderstood !

Thanks,

John Bender
 
I was looking through the AOPA document, and don't see anything that mentions that speed being under max gross, it just seems to be in general.

Also, there is a separate entry that just says "Maximum airspeed of 120 knots." which doesn't mention altitude or standard atmospheric conditions.

I couldn't find the CFR that defines these, but it seems to me according to the AOPA page that any plane that gets above 120 kts is no longer an LSA. Do you know where the documentation that says otherwise is?
 
Gents as you will see below neither are explicitly correct. the Vne is for a GLIDER at 120K CAS not an Aircraft (separate class)

the max weight has nothing to do with the 120K limit but rather stall speed

and the sea level distinction on the 120K speed limit is correct (though without explicitly listing a weight there is a grey area, since most LSA's have a minimum TO weight I wonder if that would be the measuring stick...)

FAR Part 1 General definitions

Light-Sport Aircraft definition "...

1.) ....take off weight 1320...

(2) A maximum airspeed in level flight with maximum continuous power (Vh) of not more than 120 knots CAS under standard atmospheric conditions at sea level.

(3) A maximum never-exceed speed Vne of not more than 120 knots CAS for a glider

(4) maximum stalling speed or minimum steady flight speed without the use of lift enhancing devices (Vs1) of not more than 45 knots CAS at the aircrafts maximum certificated takeoff weight AND most critical center of gravity.

(5)...
 
There would be no other way -

to have a specified max speed without giving the sea level, gross weight, max power. Any LSA plane far under gross at 3 - 4000 feet is going to go faster than at max gross weight. I think the FAA report I referenced gives good info.

John Bender
 
The regulating documents (the adopted concensus standard) used for determining whether an S-LSA (and the coresponding E-LSA) meets the certification requirements are ASTM documents. I think the one that pertains to performance testing is ASTM F2245.
 
I think the gist of the angst is whether or not flying the RV-12 faster than 120K CAS essentially voids its airworthiness cert as an LSA.

I think that unless you were reporting greater than 120K CAS flying very close to the oceans surface or close to the ground in Death Valley and/or New Orleans, you don't have much to worry about.
 
WOT is NOT max continuous

John said that he went 126 knots at WOT. The Rotax can only run at WOT for 5 minutes, not continuously. John did not break the rules. There is no rule that says that a LSA can not momentarily go more than 120 knots. The LSA rules define the capabilities of the aircraft, not necessarily how it is operated. If the RV-12 is cruising along level at 120 knots and the pilot pushes the stick forward and speeds up to 130 knots going downhill, then doing that does not disqualify the LSA status of the aircraft. Nor does flying faster than 120 knots at full throttle for a few minutes.
If a builder adds a turbocharger and reduces airframe drag and adjust the prop so that he can cruise cross country at speeds higher than 120 knots, then the plane is no longer a LSA. And it would not matter how the RV-12 was registered, E-AB or E-LSA. A sport pilot could not legally fly it, ever.
Joe
 
Interesting.

The real question I'd have is: What happens if you are registered as E-LSA and say, repitch the prop so that cruise is above 120 knots?

You immediately can no longer be an LSA plane ever again, but do you lose your AW cert? If so, what can you do to fly the plane again?
 
Here's the truth - -

At max wt, at sea level, WOT, level flight, you can't get this plane to exceed the 120 knot speed no matter how you pitch the prop. However, much lighter than max, at 3 - 4000' MSL ( in my area ), it will go over 120 knots. It is NOT an issue. Sorry I accidentally started this discussion. Thought it was understood, but as I said originally, it is not well understood. Scott quoted the correct ASTM. This plane meets LSA requirements properly !

John Bender
 
All's I know is...

Thanks for the updates John.....us builders in progress appreciate hearing of your experiences with your -12....and especially that "heater door" mod.....keep the feedback coming!
 
THANKS DENNIS !

As I have stated, the Heater Damper Door mod by far adds the most comfort for us folks in colder climates. I have flown when the outside temp is ZERO F. That is cold by almost anyone's standards. I can make it VERY warm even then. Run the CHT's up to say 205 F, and WARM air comes out of the heater.

John Bender
 
Hey Dick - -

Most of these discussions can be of benefit. To others they may seem less so. This is important to know for all involved with LSA.

John Bender
 
fascinating thread, but seems to me to be much ado about nothing. Dick Seiders

Pretty much sums up my thought on the thread drift.


Congrats John, and thanks for all of the mods you have come up with for the -12. All are worth while additions.

Now, how about alerion trim? ;)
 
John said that he went 126 knots at WOT. The Rotax can only run at WOT for 5 minutes, not continuously.

5 minutes of WOT??? I have been flying Rotax engines in LSA's for 3 years but have never heard of this limitation. I am not saying that it is not true. How do you define WOT? over 5200 rpm? As I am typing this I realize that if I am at full throttle and the rpm's go over 5200 I pull back to keep the rpm's below the yellow checkered and red part.

so maybe I answered my own question :D

Pieter
 
Hey Pieter - -

This is getting far away from where it started, but still can be good info. ROTAX considers 5500 RPM to be "max continuous power". It is ok to run the engine up to 5800 for 5 minutes per their manual. If you don't have the prop pitched to be able to go over 5500 RPM at WOT in level flight, ( and maybe light on weight ), then you don't have the prop pitched right. Hope this help answer your questions. Also hope this can be the end of what I wanted to start as an up-beat positive thread about having a good flying day and 200 hours !

John Bender
 
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Need to keep the facts straight...

This is getting far away from where it started, but still can be good info. ROTAX considers 5500 RPM to be "max continuous power". It is ok to run the engine up to 5800 for 5 minutes per their manual. If you don't have the prop pitched to be able to go over 5500 RPM at WOT in level flight, ( and maybe light on weight ), then you don't have the prop pitched right. Hope this help answer your questions. Also hope this can be the end of what I wanted to start as an up-beat positive thread about having a good flying day and 200 hours !

John Bender

You are right John, people are confusing the difference between WOT (wide open throttle) and engine speed above 5500 RPM.

The limit is a 5 minute max. operating above 5500 RPM.
I have flown the RV-12 for hours on end at WOT at 12,500 ft (not as a Sport Pilot) but the manifold pressure was only about 20 inches.
 
Rotax 914

Regarding the question of 120 knots at sea level...

When I test flew the Rans S-19 with Randy Schlitter out here in Utah, he made the comment that if he was building one here, he'd put a 914 in it. I asked whether that would make it go faster than 120 knots and no longer be Light Sport. He replied that the 120 knot limit was at sea level, and all the turbo-charger would do was assure that you'd still get sea-level performance from the engine at higher altitudes. So your IAS would still be 120 knots or slower, but your TAS might be well above 120 knots.

I'm not sure if this works out or not. But's interesting to me that the first Rans S-19 in Utah was built with a 914 rather than a 912. I haven't seen any reports on the performance it gets. But he didn't build as a light sport. He included a in-flight adjustable pitch prop.
 
914 vs 912

Sounds Great! The price of the 914 vs the 912 is about $10,000.00 more and it burns more fuel and runs hotter to. :eek:

John
RV12 N1212K
 
The big problem with violating the LSA limitations is that - as the FAR is written - if you EVER, even ONCE exceed any of the limits, the AW is invalidated and the aircraft is never eligible for an AW again. Pretty draconian. Of course, that's the way they're written. What the FAA is going to do is really yet to be seen.

As others have clarified, the 120KT issue is SL, ISA and max continuous power. There is no limit on weight or CG with respect to the 120KT limit. However, as we know, flying the airplane light and at the aft CG will make it faster. Thus, it is certainly possible to see > 120KT without violating the FARs. I often see > 120KT IAS and TAS in the CT when light and aft CG, and at colder than ISA.

As for building a LSA that isn't an LSA, I'd stick with the 912 and go with a CS or in-flight variable-pitch prop. This gets you full power out of the 912 in climb-out (getting to around 5500 RPM) and allows you to get lower RPM in cruise, lower fuel flows and still plenty of speed (4800-5200 RPM). Several European LSAs have variable-pitch props and, along with negative flaps, get 140KT or more out of the 912. The 914 works well at high DA, but costs a LOT more and is much more complicated. There are lots of 912 CS applications (e.g., DA20-A1 Katana, HK36 motorglider).

TODR
 
Hey John, I agree on the thread. (I said it was fascinating). I suppose what I was trying to say is if one flies at greater than 120 kts why talk about it if it gets so many folks uptight about losing AW?
Dick Seiders
 
This is getting far away from where it started, but still can be good info. ROTAX considers 5500 RPM to be "max continuous power". It is ok to run the engine up to 5800 for 5 minutes per their manual. If you don't have the prop pitched to be able to go over 5500 RPM at WOT in level flight, ( and maybe light on weight ), then you don't have the prop pitched right. Hope this help answer your questions. Also hope this can be the end of what I wanted to start as an up-beat positive thread about having a good flying day and 200 hours !

John Bender

Thanks John for the extra explanation, I did not mean anything bad with my reply.

Just finished 90 minute flight in Rotax powered tecnam eaglet :D it was a great day for flying
 
I just happened to do the math - that WOT covers 145miles in an hour, with a fuel burn of approx 26.4 mpg! Pretty darned economical I think with no slouch of speed either. I am impressed! Is this with or without wheel pants John? I am the type that will want to do some speed mods to shoot for 150 mph. Is that do-able?

At the speed I was going, it was showing about 4.9 GPH of high test auto fuel most of the time. I would guess I was at about 75 - 80% throttle. The picture shows 112 knots indicated. I was able to get 126 knots WOT earlier that day. At WOT, it shows about 5.5 GPH.

John Bender
 
Hey Don - -

With Painted pants. Weather, density, etc, all have an influence. Some days I can not get to 120 knots WOT, even by myself. At moderate cruise of say 125 MPH ( 108 knots ), I see 25 MPG usually. Not bad at all. Fun plane for just going no where in particular ( which is what I do a lot ) !

John Bender
 
I can see you need to change your habits!
Come on down to the Rio Grande Valley to test your plane and your own cross country skills, and fill up the baggage area with fresh grapefruit and oranges for the unfortunate Iowa people.
Flight plan for T65, I will pick you up, after going over your RV with a fine tooth comb, I have only seen one so far!
PS: The fresh fruit and dinner are on me.
 
Hey Don - -

After our first foot of snow, that may sound like a great idea. Wife might not think so, but sounds like fun. Thanks for the great offer ! ! ! !

John Bender
 
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