Thank you Colin I printed your reply. Bill Starrs ----- Original Message ----- From: "Colin Rainey" <brokerpilot9...@earthlink.net> To: <kr...@mylist.net> Sent: Friday, October 21, 2005 10:47 PM Subject: KR> Testing and speeds, and weights
Thanks for the compliment Orma. I will try to measure up to the expectation, though I am only 5'5"....haha On a more serious note, a 60 degree bank in a LEVEL coordinated turn results in a 2 g load on the aircraft, or basically doubles the aircraft weight through load increase, and increases the stall speed of the aircraft 40%. This means that an aircraft that stalls at 55 mph will stall at 77 mph in a 60 degree level bank turn! These are aviation constants that we CFI's teach pilots. A level turn of 45 degrees bank exerts 1.5 g load. Stalls while doing these maneuvers is referred to as accelerated maneuvering stalls due to the increased stall speed caused by the increased load during the maneuver. Early in my KR testing I went out over the water just off the coast of Massey Ranch, home of William Wynne. It is my designated test area and has a great view of the NASA Shuttle Assembly building and launch platforms. It also gives me a VERY long emergency runway called a beach! Anyhow, I climbed up to 5,000' and began to get to know its behavior with gradual entry into both power on and power off stalls. They came on very gently, and I quickly began to have confidence that this airplane was going to fly very similar to the light twins that I enjoyed so much. As part of your CFI ride a candidate must demonstrate a secondary stall. Having taught several CFI students already, as well as remembering my own training, I began evaluating the KR for its behavior in a secondary stall. My plane's reaction compared very much to the subjecting a horse to an electric cattle prod. You might stay on, but it was gonna be a rough ride! The most memorable portion was the violent drop of the nose, accompanied by a negative g or 2, (my flight bag went to the ceiling), and the hard roll to the left. My next impression was that someone had snuck a NOS bottle on board, and had punched the button on that nitrous because the speed was now growing with tremendously rapid rate compared to other aircraft I had flown. I leveled off and noted my altitude and realized that 2000' had evaporated in what seemed to be less than 1 minute. This experience gave me a grave respect for getting this wonderful little bird too slow. I have spoken before about how to plan your landings in winds by adding half the gust factor to your approach speed, which has allowed me to successfully land our KR in quartering crosswinds as high as 25 knots (according to the E6B conversion chart 15 knots @ 90 degrees which compares well with a C172). My reason for pointing out the change in stall speed during maneuvers, is they also change with weight change. As you get heavier, your stall speed will increase. When first beginning to look at KRs for purchase, I read the NTSB reports on Mark L's site. A quick study of these reports found that virtually all the pilots who crashed their KRs were caused from getting too slow near the ground either on take off or landing. This aligns well with overall accidents in general aviation, that 75% occur near airports during takeoff and landing phase. From a statistical point of view, the cross controlled stall in the base to final turn has claimed more pilots than any other single maneuver, especially low timers. I am not speculating on Steve's accident. Merely relating it to the facts Mark Jones presented in his post. AOPA Air Safety Foundation sent out a newsletter this past year with several articles about the hidden danger of the base to final turns and low altitude stalls. My conclusions were that the KR is to be treated like a Mooney or Bonanza, and flown AWAY from the minimum speeds, and use things like flaps and speed brakes to help bleed off excess speed during round out and flare. I have always been bothered by pilots who brag about how slow they can get their KRs. First, all builder/pilots should know we don't have calibrated ASI's so no one knows for sure what speeds they are running. I keep hearing pilots compare to GPS, but that is GROUND SPEED not airspeed. So BE CAUTIOUS and test your speeds for stalls, etc... at altitude to find out where your stalls will occur solo, and then again with weight. You will find they do change. All high performance aircraft are unforgiving slow and near the ground to mistakes, KRs included. This one's for you Steve The Southern Rebels are playing Amazing Grace.... Colin Rainey brokerpilot9...@earthlink.net KSFB _______________________________________ 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
