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King Katmai v. Cub

sjohnson

FRIEND
Boise, ID
I was talking to a couple of friends the other day. One just sold his Carbon Cub and wants to buy a 182 for doing cross countries. The discussion got around to the King Katmai conversion by Peterson.

Peterson advertises the stall speed as 31k at 3100 lbs. The original stall speed for a 182Q is 50 KCAS (dirty, power off, most rearward CG) at 2950 lbs.

31 kts is 62% of the original stall speed, or about 38% kinetic energy. This doesn't seem aerodynamically possible without lengthening the wings, which I understand is not part of the conversion. There simply isn't enough energy in the airflow.

Micro shows a 8% reduction in stall speed for its VGs. The Katmai canard might help a little, but it cannot be too powerful - if it overwhelms the tail, it could induce a deep stall.

So how is this possible? Is the 31k number power on? KIAS instead of KCAS?

Flight reviews (from the Peterson website) describe touchdown speeds ~35k, presumably indicated but not at gross.

Landing roll goes from 560' to 290', which also seems suspect. Even at the published stall speed, given the energy change (assuming touchdown speed scales), the ground roll should be around 350'.

The Peterson published numbers are roughly equivalent to stock Super Cubs, a plane with much lower power loading and just over half the weight.

Anyone have experience with these?
 
All those numbers are about right - hard to compare apples-to-apples when you’re talking about a wide variety of “runway” surfaces in bush flying. I’ve got some time in a late model Katmai and it’s pretty amazing. Mains off the ground at 30 to 35 knots in ground effect - more or less routine for takeoff. Same for landing. Nose wheel easily controlled. With even a little power the canard keeps the nose wheel off the ground. Hard to beat the envelope from stall to normal cruise airspeed range. Go fly one. It’ll make a believer out of you.


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Robertson listed the stall speed of the RSTOL Cessna 185 at 37 knots, and I firmly believe that number. So, pretty comparable reduction in stall speeds. I’d believe it.

its a bitch to remove the cowlings on those Katmais though.

MTV
 
Are the speeds you're providing KCAS or KIAS?

My 182Q manual shows a pretty significant error: 50 KCAS is 38 KIAS. This would explain some of the apparent phenomenal results.
 
In the early years when the Wren conversion came out, there were a few up in Alaska.

Bill Ellis had picked one up that had some issues and got it back flying; he was impressed with it's performance.

Wish that conversion was available on the 206!
 
does the canard seem to get in your field of view?

Didn’t bother me at all. The canards are positioned low enough not to impede forward visibility during ground movement and the span of each canard is inside the prop arc. So...since it’s a nose wheel, the taxi visibility is better than just about any taildragger and once you’re rolling for takeoff you’re looking well beyond the area blocked from view by the canard - even with the nose high soft-field takeoff.
 
I fly a peterson modified 182 with canard. I have not landed it off runway and I havn't even begun to take it to its limits. Mine is the older version with the 260 hp engine. On take off, it goes into ground effect scary quick for as heavy as it is, and then rises nose flat like you are in an elevator. When landing, you have to hold it up until it is slow enough or it will just keep flying. Once you cant keep it up anymore and the mains touch the runway, it is rare to roll 200 feet. I don't know what else to say. It is an easy plane to fly and land, I have flown regular 182's and there is no comparison at slow speeds.
 
I have a King Katmai on order and it should be arriving in September or October. I flew with Todd Peterson and he is a very good stick. The plane is amazing There are wing extensions on the King. Just over 30 knots and the plane is in ground effect dead flat. You can make a steep turn at 45 knots which happens very quickly. We stalled the plane at about 31 or 32 knots. The break is a non event. Just release a little back pressure and add a small amount of power and it is flying again. I have a super cub 180 as well and plan to love them both.
 
I was talking to a couple of friends the other day. One just sold his Carbon Cub and wants to buy a 182 for doing cross countries. The discussion got around to the King Katmai conversion by Peterson.

Peterson advertises the stall speed as 31k at 3100 lbs. The original stall speed for a 182Q is 50 KCAS (dirty, power off, most rearward CG) at 2950 lbs.

31 kts is 62% of the original stall speed, or about 38% kinetic energy. This doesn't seem aerodynamically possible without lengthening the wings, which I understand is not part of the conversion. There simply isn't enough energy in the airflow.

Micro shows a 8% reduction in stall speed for its VGs. The Katmai canard might help a little, but it cannot be too powerful - if it overwhelms the tail, it could induce a deep stall.

So how is this possible? Is the 31k number power on? KIAS instead of KCAS?

Flight reviews (from the Peterson website) describe touchdown speeds ~35k, presumably indicated but not at gross.

Landing roll goes from 560' to 290', which also seems suspect. Even at the published stall speed, given the energy change (assuming touchdown speed scales), the ground roll should be around 350'.

The Peterson published numbers are roughly equivalent to stock Super Cubs, a plane with much lower power loading and just over half the weight.

Anyone have experience with these?
It's called specsmanship. Calibrated airspeed, gross weight and power off stall speed don't impress anybody so they are avoided by most mod companies.

Sent from my SAMSUNG-SM-G900A using SuperCub.Org mobile app
 
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