Carbon Cub makeover: the Ultimate Amphib
Jim Richmond and I were doing some planning for 2015 recently and we were pining about not having a way to demo the new Aerocet amphibs once we get into the nice spring weather next year. The Carbon Cub on those floats is just cool beyond words, we just know that more pilots would want to buy them if they could experience it for themselves, after all there's only so much you can get from pictures and videos. Yet dedicating a company aircraft to that is a bit expensive given that floats are a relatively narrow market. What to do? Well, we just happen to have an aircraft in our company fleet that we thought of... N56XC, hmm.
N56XC background
N56XC was built from Carbon Cub EX kit #0009 in 2011, so it has the EX tail feathers and so on. The reason for the original project was Jim's: "what would a Carbon Cub do with an even bigger engine on it?" So, Jim bartered a deal with Bart Lalonde at Aero Sport Power for an O-375, and as long as he was going big he went all the way, "let's put 10.0:1 pistons in it too". And, "as long as we're going big let's try a constant speed prop on it too, we've got an extra MT around here somewhere". And so the plane was built with this big-assed engine, constant speed prop, and a few other tweaks we were curious about as well. What would happen, how would it perform?
Turns out that an engine like that with high compression and electronic ignition creates a combustion event, and associated pulses and harmonics, that simply aren't compatible with some props. In fact N56XC caused at least partial failures of two MT constant speed props and one Catto fixed pitch prop before the first year was out -- it quickly became known around here as the engine that eats props, and got to where we weren't sure it was even safe to fly. Bart offered to swap for 8.5:1 pistons, which eventually we did. Craig Catto then made yet another prop for it and it has now been stable with no damage for over 150 hours now. That's not the end of the story though.
Now you'd think this plane would just strut around boasting a superiority complex to all the normal Carbon Cubs with it's big-assed engine and all. Turns out that's not the case. I've personally flown N56XC several times now in a tight formation flight missions including takeoff, full power climb, and flat out level run with new Carbon Cubs just off the production line. No kidding, the stock Carbon Cubs will usually out gun me in climb and top speed both by a small margin. Go figure.
N56XC has been used in the intervening years for various other tests of course, but we can't use it for many things we want to try because it isn't a conforming LSA Carbon Cub. It is commonly a camera ship or a chase plane, and Jim typically loads a couple of kegs of his home-brewed beer in it each year and flies it to the Johnson Creek fly-in, but otherwise it sits on the ramp outside a lot. Well, I remember how freakishly fast it was for those few short hours I flew it with the constant speed prop, and it does have lower compression pistons it in now, so maybe... we'll you get the idea, the project was forming.
The makeover project
Now that you have the background on this aircraft let's talk about the makeover project. The idea here is to give a "refresh" to good 'ol N56XC to include the following:
- Install new Whirl Wind carbon fiber constant speed prop
- Refresh the weathered Poly Tone portion of the paint and clean up the cosmetics a bit
- Update the Dynon Skyview to the latest touch screen offering, and install their autopilot to complete the Dynon suite
- Put it on a new set of Aerocet 1500 amphibious floats
- Collect performance data and see what it'll do!
The point of all this is to create a showcase airplane to show just what a builder can do with an EX-based aircraft and a little creativity. We know from the regular Carbon Cub float installs we've done that floats don't slow the plane down in cruise, and with the c/s prop I'm hoping to see cruise speeds significantly higher than what a normal Carbon Cub will provide. That speed, and with the big tanks, should extend the cross country capability of this plane to a hopefully impressive level. Add to it the fact that you can land on the water or the land once you get there and you see why I'm inclined to call it "the ultimate amphib".
The plan is to start on this list of upgrades immediately and work on them over the winter as time allows, then fly the plane to Florida in April for Sun-N-Fun 2015 to show it off and do some demo flights for those interested. We're busy around here and this list will take some time to complete so we're starting today on it, in fact the prop install starts tomorrow. As a two time aircraft builder I've been without a project for quite some time now, so Jim and I agreed that I'd take this on as my personal project. Cool, I'm stoked!
The plan is to fully document this project and my journey to Florida right here in the forum. Look for additional posts as we make progress, of course complete with pics, maybe even a little video from time to time.
Following along
If you'd like to tag along and monitor my progress you might want to "subscribe" to this thread -- just click the "Thread tools" menu at the top right of this thread and click on "Subscribe to this thread". You'll then receive an email whenever there is an update to this forum thread. For those unfamiliar with this forum software you need to be Registered in order to see the pictures. If you are not registered there's a link to register at the top right. Please note that if you are registering for the first time the system will send you an e-mail with a link in it you'll need to click to validate your account. If you'd like a quick and simple briefing on how we have the forum set up click HERE.
Lastly, I'll leave the thread open so you can let me know what you think if you like.
Stay tuned!
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Originally Posted by randylervold
