Did you actually measure the CG when you were sitting in the plane or is this a theoretical calculation?
Jim Faughn 891JF -----Original Message----- From: krnet-boun...@mylist.net [mailto:krnet-boun...@mylist.net] On Behalf Of countryhomeprint Sent: Thursday, March 30, 2006 11:21 AM To: KRnet Subject: Re: KR> cg with Deihl wing skins Larry, my cg falls about an inch from the front limit empty. With full gas it falls about 3/4 inch from front limit. This was determined with two calculations with two different datum points. Each fell at approximately the same distance from the front limit. With a 180 # pilot, the cg falls approximately 1 1/2 inches from the front limit. With the cg this far farward it could create a tail heavy situation. However, as the craft slows, the back stick forces become less. The incidence is exactly as the plans call for. I used an electronic level to determine this. The dihedral is exactly as the plans call for, again determined by electronic level. Also the twist at tip is right on. Ball was centered. Reaction was such that there was instant stick forward and it recovered. Stall was never reached, however, the airspeed was reading between 48 and 50 mph. After Sun n Fun I am going to place 10 pounds forward and re-calculate the cg. Then 15 lbs., 20# --- until I reach the center of the cg range. Then a careful flight will be made. Verified level flight at 2500 feet at 2800 rpm is 135 mph. Bill Page boliverp...@bellsouth.net ----- Original Message ----- From: "Larry&Sallie Flesner" <fles...@verizon.net> To: "KRnet" <kr...@mylist.net> Sent: Thursday, March 30, 2006 8:25 AM Subject: KR> cg with Deihl wing skins > > >> Is the cg range for Dan Deihl wing skin wings the same as for the >> standard KR-2 wings? N880AB's cg falls within the limits for the >> standard KR-2, however my KR feels tail heavy. I am unable to >> establish a true stall due to the uncontrolled pitching up of the >> wings prior to stall. It feels as if the horizontal stab and >> elevator are stalling prior to the wings. >>Bill Page > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > > As others have mentioned, the Diehl skins should have no effect on the > C.G. > range of your KR. Their only difference,over the plans built wing, is a > bit of > additional length. Can you give us more info on the stall / pitch-up? > Where > EXACTLY does the C.G. of your KR fall in relation to the plans? What did > you do to recover or did the KR recover on it's own by dropping the nose? > Do you know the angle of incidence your wing is set at? Did it require a > lot > of back stick to hold the nose up to approach the stall? Was the ball > centered > at the time of "pitch-up"? Consider the following. If it's a CG problem > and > your KR is tail heavy, the recovery would seem difficult or > impossible. If it's > nose heavy, and you stalled the HS / elevator, it seems the nose should > have > pitched down. There are too many variables between KR's to GUESS what > your problem might be without additional info. > > While my KR is stretched 24 inches, the wing and tail are plans built and > set to "plans" angles. My KR has a VERY GENTLE stall with complete > aileron and elevator control up to and through the stall. I get no wing > break off or other unexpected reactions. This seems to be the "normal" > stall characteristics for most KR's and how your KR ought to perform. > I can understand your wanting to determine the cause before additional > testing. When unexpected things happen in a new airplane it can scare > the hell out of you. > > Larry Flesner > > > _______________________________________ > Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp > to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net > please see other KRnet info at http://www.krnet.org/info.html > _______________________________________ Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp to UNsubscribe from KRnet, send a message to krnet-le...@mylist.net please see other KRnet info at http://www.krnet.org/info.html
