| The BK instrument is a lift reserve indicator, not a stall indicator. It is meant to augment aircraft with stall indicators. But, the primary purpose for you Doug is to show the Donut "on speed" at your desired 1.3 Vso if that is where you want to fly your approach. After reading the literature I would just set the optimal for that speed based on your weight for 1.3 Vso and go fly.
The device should show you best speed for downwind, base, final and anything slower than "optimal" will start calling out warnings up to the third warning. But, this unit isn't providing stall warnings so it is possible to stall before getting to your last warning. That's a potential problem so you either stay out of that zone or test it up in that area in a safe manner.
I use the Advanced AOA and we just set the 1.3 Vso plus a few other settings so this BK isn't much different. You don't have the ports in your Legacy wing for the Advanced device I assume.
Sticking this thing out in the airflow is going to offset your hinge mod….
Paul Terrence, There is no “angle” to mark. Both instruments use an array of colored lights - in both, the top colored light is a red arrow pointing down – presumably this is to indicate a stall. The way that both are made to be used is to define a safe speed (roughly 1.3 Vso) that can be used during landing (and other maneuvers) My question was whether to set it to 1.3 Vso or to do the maneuver described in the setup. D. Brunner D., IMHO the prime purpose of an AOA is: To make the wing's STALL ANGLE visible to the pilot. You do that by flying the plane and stalling it as you watch the AOA... then mark that angle. The next most useful AOA info is the best L/D or best R/C... done the same way... fly the plane while watching the best R/C for a given power setting, and make that angle. On Mar 30, 2014, at 9:23 AM, Douglas Brunner wrote:
I am thinking of adding an AOA to my plane. The two models that I am looking at are the Bendix King KLR 10 (http://www.bendixking.com/Products/Flight-Controls-Indicators/Indicators/KLR-10) and one of the Alpha Systems units (http://www.alphasystemsaoa.com/) My question has to do with the calibration. Both systems require a calibration at 3 points: The “on ground” and “cruise” are self explanatory, however the definition of “Optimum Alpha Angle” seems a little “loosey-goosey” to me. Here are the definitions: Alpha Systems “Optimum Alpha Angle” · Able to hold altitude – as close to 0 VSI as possible, zero sink · Full aileron, elevator and rudder control – no buffet or loss of control surface stability Bendix King “Optimum Alpha Angle” · Able to hold altitude, 0 Vertical Speed, zero sink (5 to 10 fpm climb OK) · Full aileron, elevator and rudder control, not in a buffet, pilot to identify the set point by pitching back slowly to a pitch no longer able to climb but able to hold altitude with full First of all, since this is a system meant to be used in landing (or at least that is how I will mostly use it), I intend to calibrate the “Optimum Alpha Angle” in landing configuration (gear down, full flaps). However, determining when I have “full aileron, elevator and rudder control” isn’t all that clear to me. I am sure that I can tell when I have aileron, elevator and rudder control – but the “full” part is less clear. Does that mean a full control deflection? Not something I am anxious to try that close to stall. Alternatively, I could just do a stall in landing configuration and set the “Optimum Alpha Angle” to 1.3 x stall. D. Brunner N241DB 750 hours |