HI, where can one find the information on locating the mains vs. c.g ? thx mike On Sun, Mar 18, 2012 at 8:06 PM, Barry Kruyssen <k...@bigpond.com> wrote:
> Hi Dan > > I have a Jabiru 2200 in my KR2 and it is wonderful. > > I also think that you are too far back in the CofG range. Don't add weight > permanently. Add weight to confirm this but just lengthen the engine mount > and cowl. > > See http://www.athertonairport.com.au/kr2 for details on my KR2 > And about three quarters down the page is a link to how I did my W&B > (direct > link http://www.athertonairport.com.au/kr2/w_and_b.htm ) > > I did have a problem with my new undercarriage as I mounted the mains too > far forward. Solo this was not a problem. But two up was different, I had > too much weight on the tail when taking off and could not lift the tail > before the main wing started to fly in ground effect, scary stuff. After > much research I found that there is range for the undercarriage in from of > the CofG, so I changed the mounting brackets and fixed that. Now it is > perfect. > > Feel free to contact me regarding any aspects of my Jabiru installation. > > Regards > Barry Kruyssen > k...@bigpond.com > > -----Original Message----- > From: krnet-boun...@mylist.net [mailto:krnet-boun...@mylist.net] On Behalf > Of DAN INA GLANDT > Sent: Monday, 19 March 2012 8:37 AM > To: kr...@mylist.net > Subject: KR> first flight problems > > > Hi, > After getting the brakes to work smoothly and completing my biannual flight > check the day before, I tried the first flight test of my KR2S conventional > gear with Jabiru 2200. > It was a good day with a steady > headwind of about 10 mph right down the 6000? runway. The plan was to > take > off and fly > along at 20 to 30 feet and then land. > I got off the ground quickly at > about 75% throttle. I expected that I would have had to apply some back > pressure to the stick to lift off and climb but did not. > > The plane nosed up and climbed to 30 feet or so, then slowly nosed down > some > to about 20 feet then the nose started back up. This happened like 3 > cycles. All the time I am holding the stick as steady as I could in pitch, > not wanting to aggravate the situation and get into PIO. I felt no > feedback > stick pressure either forward or backward. > I reduced power slowly and lost altitude until it felt safe to flare. Then > I reduced power and slowly applied back pressure. The pitch oscillations > continued. > > I could not hold a steady pitch angle as I flared. The landing was in a > word wild, but successful. I can attest that the gear is rugged. The > plane > never felt like it was going to stall. > It just settled. With no feedback pressure, it basically felt as if I had > no > control. > > The safety person watching is a pilot and said it looked just like one of > his radio controlled models he flew that was tail heavy. > > The next day, we did a weight and balance with 6 gal of fuel in the header > tank and myself in the plane just as it was during the flight. The cg was > 12? aft of the wing leading edge, the center of the range. The empty > weight > is 640 lbs. > > I can add 20 lbs of weight right behind the engine but it > will only move the cg to 10.93? aft of the L.E. As fuel burns off, some of > that gain would be lost. If I add 40 lbs to the front, the plane will > probably fall on its nose when I get out. > > The control cables from the bellcrank behind the rear spar to the elevator > are tight. There is a small amount of play where the control stick mounts > in the cross tube which connects to the bellcrank via a push pull tube. > Because of the looseness at the bottom of the stick, the top of the stick > can move at the most 1/8? for/aft before the elevator moves. > > I have a feeling that I am overlooking something and I hope to receive some > comments that will help explain what happened and some ideas for a > reasonable remedy. At this point, it appears that it is a cg problem. I > am > 5? 10 ½ ? and weigh 190 dressed for the flight. Losing 40 lbs would be > good, but > probably not realistic. If > the plane is that sensitive to cg location, it looks like carrying fuel in > the wing tanks or any luggage would be out the question. > > Dan > > > _______________________________________ > Search the KRnet Archives at http://mylist.net/private/krnet/ > to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net > please see other KRnet info at http://www.krnet.org/info.html >
