Got to fly a KR2-S

[Schmleff]

I got to fly solo in a friend's KR2-S tonight. Here was my write up to the KR guys that gave me pointers on how to fly one. For reference, it is powered by a 2700cc Corvair and has the latest mods including their new airfoil:

Flew it for about a half hour tonight. Everything worked as it should have.

Takeoff was uneventful. Accelerated to about 40, brought the tail up,
lifted off at about 60ish. Leveled off in ground effect and
accelerated to 100. Let it climb out at about 110mph showing about
1200fpm climb.

The site picture is very different than the Sonerai. For reference,
mine is a Sonerai I which is more sensitive than a 2 seat Sonerai.
Back to the KR... The nose sits higher in cruise than I would have
expected, but I was only going about 140mph. I expect that it will be
lower at higher speeds. As far as stability goes, wow... My Sonerai
is completely neutral in all axis which makes it a full time workout
to fly. The KR's yaw stability was great, the ailerons were heavier
than I expected. The pitch sensitivity is much less than my Sonerai.
I was amazed that I could actually take my hands off of the stick! My SI is so sensitive
that I can barely fly it with my left hand.

The first set up for landing I was too close to the runway on downwind
and ended up going around. In the SI, I usually fly the pattern at
145, slow to 120 as I turn base, bleed it down to 100 for the turn to
final and 80 over the numbers. With the KR, I flew the pattern at 120,
reduced to 80 abeam the numbers and put in a the first notch of flaps.
I flew a long wide downwind so I could get set up for the runway
better. On my turn to final, I was going 80 and dropped full flaps,
but was too low. I had a bit of trouble judging my altitude and had no
forward visibility. I put the power back in to clear the trees. After
clearing the trees, I was going 70. I had the pitch trim set to full
up, a trick I used in my Piper Pacer that seemed to make landing
easier. Again, for reference, my Sonerai has no flaps or trim. I held
70 in a gentle descent and flew the plane on with no flare. I was
actually surprised that the mains touched down as soon as they did but
the contact with the ground was smooth so I pushed the stick forward a
bit and let it roll down the runway without braking. Eventually the
speed bled off and I put the tail down and held it there. It tracked
straight down the runway with minimal rudder input.

In summary, it flew great. The mission of the Sonerai I and the KR are
quite different and each has its place but the KR seems to be a much
easier to handle on the ground and in the air. My SI does however have
much better visibility in all aspects of flight even though it is a
mid wing. I really like the way the KR flies and its is much better
suited for cross country than my SI. I have long been an admirer of
the KR and am glad to have gotten the chance to fly it!

One other thing caught my attention and that was how much quieter it
was in the cockpit.

I am going to put some more time on it in the next month and if all
goes well will fly it to the KR gathering with my daughter. If
something comes up with the KR I will be there in the Sonerai.

I did have the GoPro running for for the landing and will share the
link when I get it edited and uploaded.

Jeff Lange

 

[mhflyit]

Jeff,
I hadn't heard great things about the KR2 but your summary enforces the point about not drawing conclusions too quickly!

How less sensitive is the S2 compared to the S1?

 

[Schmleff]

I don't know. Ed Fisher knows. He has flown both. The only Sonerai, one or two place I have is mine.

 

[bobthebuilder]

I too have not heard many positive comments about the KR2.
If you were in the market for a two seater, would you buy, or build one, or would you rather look at something else?

 

[Schmleff]

It depends on the circumstance. I would buy one if the price was right.

What had you guys heard bad about them?

 

[Raceair]

mhflyit..........I would say that the Sonerai 1 is 50% more sensitive in yaw, 25% more sensitive in pitch, and 'about' the same in roll, as a standard Sonerai 2. A Sonerai 2, in the air, feels a bit like an American Aviation Yankee, But the Sonerai 1 feels more like a Cassutt, or a Pitts, Especially on landing, it compares to a Pitts. The Cassutt, on the ground, is actually easier to track than a Sonerai 1, unless, of course, you put the Sonerai 1 gear on backwards, and then it becomes a bit more calm....Ed F.

 

[bobthebuilder]

I heard that the C of G range was narrow, which cause serious stability problems if you were not within the correct range.
There was one operating not too far from here that was grossly under powered. Not sure what donkey was fitted.

Steve Boschoff, who now lives in New Zealand I think, tried to perfect the design. He called his variant an SB2. It apparently addressed some of the stability issues.

 

[JuergenA]

if anybody ask me about the flying characteristics, I answer:
It fly like a TMG, but a bit more sensitive, because it have the same engine 8)
(you must know, most of the German TMG's use VW engines )
Juergen

 

[mhflyit]

Ed,

I'm just excited to get my S2 flying and, after having it test flown , find out for myself - in the sporty category I have flown RV6's and an 8, AY's and most recently until this build was renting a Liberty XL (based on the Europa) which is pitch sensitive but was a joy to fly - compared to Cessnas and Pipers...

In ref to the KR2, we all know planes can get a bad rap in the hands of a ham-fisted pilot or builder for that matter!!

Jeff, I look forward to your next flight report in the KR - great reading!

 

[bobthebuilder]

In ref to the KR2, we all know planes can get a bad rap in the hands of a ham-fisted pilot or builder for that matter!!

I agree. Many of them have been built and flown safely.

 

[daddo2]

I often fly formation with a KR-2 and do have some stick time in the KR. This is the KR-2, not the stretch, with a Revmaster. Heavy in roll, much too sensative in pitch, especially with two on board. Put two adults in it with a light fuel load and you can easily develop pilot induced oscillations. This one's also a trike and there is little to no flare before mains touch down. It just plants itself on the runway. But it is comfy, good vis over the nose,climbs well with two on board, and is slightly faster than my S-2.

 

[dayflyer47]

Jeff,

Did I understand you correctly that you are saying you have t. put 25% more rudder input in your s1 to control the adverse yaw? Just trying to make sure I understood you correctly. I hve been flying a tailwheel for about 45hours and still mess up landings once in a while, not sure if I am up to the sonerai yet?

Dave