Subsequent Flights of Mark Langford's KR2S

Third flight

May 28, 2005

Today I tried out the new airspeed indicator. Markings are for an RV, but at least the flap range is correct. First I did a few taxi tests, and was temporarily amazed to see it reading almost 70 mph when I got up to my usual high speed taxi test speed. That was my second clue that it was probably going to be reading high. The first clue was the night before, when I calibrated the new airspeed indicator and it showed a 7% error in the 60 mph range. The vertical speed indicator read zero or slightly less at high speed taxi, so I was hopeful that I'd fixed the static port problem too.

I'd really decided I wasn't going to fly it, because the weather wasn't absolutely perfect, but Larry Flesner called to give me a pep talk, and I was standing right next to the plane, and decided "why not?" So I took off (that's the easy part), climbed to about 4000', and did a few power off stalls to see what my landing speed was going to be. It stalled at about 60 mph indicated without flaps, and 55 with flaps (56 mph clean, 51.5 mph with flaps, after correction), but I'm pretty sure that's still higher than reality. I did about three of each, just to make sure. The thing really just mushed, but there was some nose down break, and once or twice the right wing dropped a little, but I probably didn't have the ball centered, knowing me. I also determined that the VSI was reading a few hundred feet of descent while maintaining altitude, so the static system is less than optimal. I'd wondered if the location I chose would be in a negative pressure area, but that's where Troy's are located, and they work fine for him. Mine don't though. I think I can fix it by adding a "bump" behind each static port hole, and I'll do that tomorrow with some .060 welding rod and clear packing tape. That way I can move them around until indications are more accurate. This also means that my stall speeds are lower than measured, but I can't say how much yet. I also proved that the flaps work fine up to 100 mph, so I used them for the landing this time around. They definitely slow you down, and make a big difference in pitch attitude, for improved visibility over the nose.

Armed with my new airspeed numbers, I thought I'd try a few runway runs, but was going too fast each time to land it. On the last attempt, I was probably still going 75 (indicated, probably closer to 70) when I touched down, which is apparently still too fast. And I'm pretty sure I was overcontrolling it, so I was doing the porpoise thing (the only time I do that is during landings!). I'm going to have to chill out a little and start "thinking" about attitude changes, rather than actually moving my hand to effect them. Anyway, I did the big bounce, another balloon affair, but still maintained directional control. I'm just glad the landing gear can take that kind of stuff. The medflight pilot told me I needed to let some air out of my tires, and I'll do that (28 psi now), but the biggie is to simply slow it down and concentrate on that last few inches of altitude, as Jim Faughn mentions in his Perfect landing - in a KR? article. Unfortunately, control in terms of inches is a pipe dream for me at this point. I'd be happy with feet instead of yards! But I'm going to try to memorize this before my next flight (maybe next weekend, weather permitting). Maybe meditation will help! I think this is really the key to a decent landing...speed control. And Larry gave me an exercise or two to do at altitude before I try another landing, so I'll do that too.

Other than pilot problems, the plane flies great. But it's a world apart from the Champ and C-172 that I'm more familiar with. At the risk of fulfilling Larry's prophecy, I'm beginning to get a little "freaked out" at this landing thing. One slightly different turn of events on either of them could have trashed the plane. The guys who do their "best landings ever" the first time around in their taildragger KRs have my respect. I'm certainly hoping Bill Clapp makes it by here this weekend for some dual...

Contact Mark Langford (if you must) at N56ML "at" (replace the "at" with @)

Return to Mark Langford's KR2S N56ML.