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Constant speed prop for RV-12 Expermental?

LeoKenner

Member
Has anyone done a constant speed propeller for an Experimental RV-12?
I would much rather go that route than the ground settable option.

I know in the US it is simpler to register as LSA, but in Canada the RV-12 will be an experimental either way so I don't have to worry about any of the LSA restrictions.
 
I didn't do it, but I do go through an evaluation and found one that would be a good fit. An Airmaster AP431CTF-WWR66U. The downside is the USD $9850 retail price, but you can get it for around $8800 from Ray L. at Kaolin Aviation, who is a US dealer.

For me, the price wasn't worth the potential performance gain.
 
Determine the top speed of your RV-12 with the prop pitched for cruise, and then the best climb rate with it pitched for climb. That's the performance of the constant speed prop.
 
Thanks, Ron. Since most RV-12s have a fixed-pitch prop that is a compromise, I wonder if anyone has tried to fly one in "max cruise" or "max climb" mode? I wonder what the gain would be at each extreme end of the range—maybe an extra 5 knots in cruise and a few hundred feet per minute in climb? Who knows!
 
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If you alter an RV-12 with a constant speed prop, in the USA, wouldn't that take the airplane out of the LSA category, as per FAR's?
 
If you alter an RV-12 with a constant speed prop, in the USA, wouldn't that take the airplane out of the LSA category, as per FAR's?
You are correct that it would no longer qualify as an LSA. However, it could be registered as E/A-B. But with a constant-speed prop, it could not be flown by a Sport Pilot.
 
constant speed prop

in the US it would in eab , the add at is a neg. speed fairings might be a better plan.
 
Top Speed ?

Also remember the 12 was designed as a light sport and cruising much faster for long period of time will add stress on the airframe that the 12 was not designed for.

My View

Joe Dallas





in the US it would in eab , the add at is a neg. speed fairings might be a better plan.
 
CS prop or no, you're not going to get much more speed out of an RV-12 without an engine swap. You might squeeze 125 kt out of it... but it's not like you're going to exceed Vne or anything.
 
My goal is not to squeeze out any more performance, and I certainly don't want to exceed Vne. My goal is to not have to have the compromise of climb or cruse performance but to get both.
 
Most RVs have a speed ratio between top speed and stall approaching 4:1.
The speed range of the RV-12 is closer to 2.5:1. You will see very little improvement with a constant speed prop within this speed range.
 
Mel,

I don't read his goal as expanding the speed range. I read it as expanding the *performance* envelope. With a controllable prop, he gets to keep the top end speed, possibly with better fuel efficiency, and get significant improvements in climb performance.

To OP: There are several electric prop options that are purpose-built for the 912/914 series engines. Most are European or Pacific region products, since we lead the world here in the USA in technology.....

Charlie
 
Mel,
I don't read his goal as expanding the speed range. I read it as expanding the *performance* envelope. With a controllable prop, he gets to keep the top end speed, possibly with better fuel efficiency, and get significant improvements in climb performance.

I didn't mean to imply that he is looking to expand the speed range. I was simply stating that a C/S prop will produce little improvement over F/P on an aircraft within the speed range of the RV-12.
 
Mel,

I don't read his goal as expanding the speed range. I read it as expanding the *performance* envelope. With a controllable prop, he gets to keep the top end speed, possibly with better fuel efficiency, and get significant improvements in climb performance.

To OP: There are several electric prop options that are purpose-built for the 912/914 series engines. Most are European or Pacific region products, since we lead the world here in the USA in technology.....

Charlie

Thanks Charlie. I know the Virus SW uses an electric CS propeller. I believe it is an MT... I will start digging. :)
 
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