Bill: This now has peaked my interest because Itook over a KR2 project that has KR2s length wings but still has the KR2 length. Do you have any thoughts on this issue based on your experience? Do you have an E-mail address for Dr. Bennett or any writings or publication referances that I can look at?
Don Lively Burlington, IA 52601 ------------------------------------------------------------------------ countryhomeprint wrote: > John, Full stall was never reached due to the unexpected pitching up of the > nose of the aircraft. I talked with Dr. Bennett of the Raspet Flight > Research Lab. He experienced the same thing in a research aircraft several > years age. The area of the wings of the "Marvel" research aircraft was > increased without increasing the horizontal stabilizer proportionally. The > same situation was noted. After increasing the area of the stabilizer, the > problem ceased. Because of other modifications I made to the fuselage I may > have helped create the problem. I will let you know what results I get from > increasing the area of the horizontal stab. > Thanks for you interest, > Bill Page > boliverp...@bellsouth.net > > ----- Original Message ----- > From: "Steve Eberhart" <st...@newtech.com> > To: "KRnet" <kr...@mylist.net> > Sent: Thursday, April 13, 2006 6:34 PM > Subject: Re: KR> Horizontal stab stall > > > Martindale Family wrote: > > > >>Hi Bill, > >> > >>Please elaborate on the Aerospace Department's conclusions. > >> > >>Seems to me a pitch up would occur in these circumstances only if the > >>aircraft had its weight behind the CoG and that component is in excess of > >>the lift available from the tailplane under forward stick. Obviously I'm > >>missing something here and why isn't it reported from other Diehl wings > >>currently flying. I agree, whatever it is it is potentially dangerous. > >>Critically, does the nose actually drop at the stall itself after the > >>pitch > >>up immediately prior it? > >> > >>Cheers John > >> > >>John Martindale > >>29 Jane Circuit > >>TOORMINA NSW 2452 > >>AUSTRALIA > >> > >>ph: 61 2 66584767 > >>email: johnja...@optusnet.com.au > >>website: www.members.optusnet.com.au/johnjanet/Martindale.htm > >>----- Original Message ----- > >>From: "countryhomeprint" <countryhomepr...@bellsouth.net> > >>To: "KRnet" <kr...@mylist.net> > >>Sent: Friday, April 14, 2006 6:47 AM > >>Subject: KR> Horizontal stab stall > >> > >> > >> > >> > >>>KR-netters > >>> > >>>After consulting with the Aerospace Department at Mississippi State > >>>University concerning the pitching up of my KR-2 upon stall approach, a > >>>probable cause has been reached. The Horizontal Stabilizer is stalling > >>>prior to the wing stall. This may be caused by the longer wing by Dan > >>>Deihl. This creates a very dangerous condition. There are three ways to > >>>prevent this condition. (1) Increase the stabilizer area by increasing by > >>>several inches the length of the stab. The standard flat stabilizer is > >>>only about 50% as efficient as a stabilizer with a true airfoil which > >>>leads to the 2nd method of prevention. (2) Change the stab airfoil to a > >>>true airfoil which will increase the efficiency of the stab. And (3), > >>>Don't stall the aircraft, keep the airspeed well above stall. > >>>It has been noticed that some KR-2 builders constructed a true airfoil > >>>rather than the flat stab shown in the plans. Maybe it should be noted to > >>>other KR builders to do the same. > >>>You guys who have true airfoil stabs, where did you get your plans, > >>>technical info., etc. I would like to change my stab to a true airfoil. > >>> > >>>Maybe if I put Armorall on my horizontal stabilizer my problem will be > >>>solved. > >>> > >>>I'm still finding dingle berrys after that close call. > >>> > >>> > > The horiz. Stab. Langford has on his KR incorporates all of the > > modifications you have described short of the Armorall dispenser. His > > plane just keeps adding up flying hours. Don't know if it is proving > > anything but it seems to be well mannered. He has engineering drawings > > for all of the airfoils used on his plane. > > > > Steve Eberhart > > > > _______________________________________ > > 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
