SportCub on Mead amphibs

[JohnM]

Hey All.

The float project for our SportCub XP is completed and I have a few hours on the airplane. I have to say that I am quite pleased with the result. The SportCub with the Mead floats flys very well and handles well on the water. I would estimate that the speed penalty is approx 3-4 mph with the floats installed vs. the landing gear with 8.00x6 tires. At 1350 lbs gw time off the water is about 11 sec.

Our SportCub has had the O-200 engine upgrade, Sensenich grnd adj prop and performance exhaust. Overall horse power is probably 115-120 hp with the XP mods in place. With the amphibs installed, useful load is still 371 lbs. The SportCub is proving to be a viable amphib with the Mead composite floats installed.

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If I can figure out the video upload thing, I will try to upload a video.

John Moreland
SWT Aviation
SE Regional CubCrafters CSC

[Jim Harper]

I must say that when I was at the Sport Aircraft Expo with the folks from SWT, I got to see the floats under construction. They are, categorically the prettiest piece of work I've ever seen. Some things just look right...and these qualify as that sort of thing. Mead makes a beautiful float.

Jim

[randylervold]

No ventral fin?

[JohnM]

No ventral fin?

When I flew the CarbonCub with the new Mead installation, I first flew without the ventral fin to assess stability. I found the stability to be adequate and left it up to the new owner to decide whether to mount the fin or not. To the best of my knowledge, he has not installed the ventral fin.

The stability of the SportCub with the Meads mounted and no ventral fin is also quite good, maybe even a tad better than the CarbonCub. No plans to mount the ventral fin at this time.

John

[Clay Hammond]

When I flew the Carbon Cub on Mead's I too felt it was quite stable as-is without the ventral. That flight encompassed a flight test with a stall sequence, water landing, then a six hour X-country north to deliver.

[Pete D]

I believe the ventral was to pass a test required by certification (not ASTM but FAA which I don't think is required for LSA). The issue was when the rudder is deflected (can't remember if it is all the way or half way) the plane doesn't want to come back to center and in some situations it continues to yaw.

[JohnM]

What Pete is describing is exactly what was done to ascertain the need for the ventral fin.

With the both the CarbonCub and SportCub with Mead floats mounted, all yawing stopped without any oscillation when the rudder was released.

JohnM