Absolutely Larry! Sorry I really meant to say, in my previous questions that we prefer a bit head heavier rather than tail heavier due to the control capabilities we could leverage on using the horizontal stabilizer, correct? But not sure if anyone has tried this, say by how much (within 5 or 10 ponds at maximum?) weight that a KR2 could tolerate if the head section is heavier than the normal weight balances?
So, it could be dangerous even if the tail section is around 2 pond heavier than CG required, correct?! Kindly, Dr. Hsu On Sun, Aug 9, 2020, 1:52 PM Flesner via KRnet <krnet@list.krnet.org> wrote: > On 8/9/2020 11:30 AM, Dr. Feng Hsu via KRnet wrote: > > > > > > > > > Also, I wish to know what's the design error tolerance on the CG position > for KR (not KR2S)? Such tolerance is determined by the capacity (surface > area) of the stabilizer, correct? If there is any uncertainty about the CG > spot, or to put the last two ponds of extra luggage during loading, we > would much prefer to allow the tail heavier than otherwise, true or false? > > +++++++++++++++++++++++ > > FALSE. Tail heavy is the worst possible condition for control and there > is no tolerance. In the case of the KR2, pilots advise to stay out of > the last two inches of the C.G. range. The 2S is longer so it may > tolerate the rear 2 inches. > > Speaking of C.G. range, it is in the plans of which mine are at the > airport. I recall 8" to 16" referenced to a certain location but I > don't recall that location from memory. That range falls in the area of > 15 to 30% of MAC (Mean Aerodynamic Cord is 48" in this case as it is > measured on the center section). Someone please post the range given in > the manual. > > +++++++++++++++++++++++++++ > > > Of course we can calculate the CG point if given design information, but > I > > suspect that the ultimate verification of CG is to use 3 weight scales > (one > > on each wheel) to find out the weight balance (empty or gross) point > > perhaps. Am I correct? > > > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > > That is the only way to determine C.G. location. Place the aircraft on > scales, perfectly level, select a datum point (a reference point to > measure from) , multiply the weight at each wheel times the distance > from the datum (arm) to determine the "moment" in inch pounds. Add all > the "moments" and divide by the total weight of all scales and that > gives you the c.g. location in inches from the datum. There are many > sites on the net that give the procedure. C.G range is, in my opinion, > equal to structural integrity in importance for safe flight. Do it > right or get your affairs in order for your survivors. > > Larry Flesner > > > > _______________________________________________ > Search the KRnet Archives at > https://www.mail-archive.com/krnet@list.krnet.org/. > Please see LIST RULES and KRnet info at http://www.krnet.org/info.html. > see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change > options. > To UNsubscribe from KRnet, send a message to krnet-le...@list.krnet.org > _______________________________________________ Search the KRnet Archives at https://www.mail-archive.com/krnet@list.krnet.org/. Please see LIST RULES and KRnet info at http://www.krnet.org/info.html. see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change options. To UNsubscribe from KRnet, send a message to krnet-le...@list.krnet.org
