Sx1552 wrote:Does this mean that the Sonex design does not provide an inherent stall buffet to warn of impending stalls?
N190YX wrote:2. Pre stall buffet in low wing airplanes is generally caused by disturbed air from the wing hitting the horizontal tail surfaces. In Vee Tail (and Y Tail) airplanes (Waiex and Bonanza) much of the tail surfaces are above this disturbed air, so not so much (if any in some configurations) pre stall buffet is experienced in these airplanes.
builderflyer wrote:it would necessitate that nearly every flight would be a practice flight and that's not a realistic expectation.
builderflyer wrote:[snip]... my suggestion of utilizing an audible AoA, which provides a warning considerably above stall speed ... [snip]
JCollinet wrote:Just my two cents based on a serious problem my aerovee had when I first acquired it...and one I KNOW others have had. First several flights in my second hand Onex (090) I had multiple engine shut downs shortly after landing due to vapor issues. A couple while taxiing back to the hangar or from the pumps, but one immediately after landing right on the runway. Not cool. (Literally)
I pulled the airplane from service and started seriously scrutinizing the location of the fuel system relative to the exhaust and the amount of airflow under the cowl. The stock exhaust runs WAY too close to the fuel system (absurdly close in my aircraft) and there is simply not enough airflow I under the cowling to cool things at low speed. Consequently when slowing down in the pattern the airflow drops even more, the temps go up, and the fuel vaporizes.
My solution was to chop the exhaust and move it to a completely different location, far from the fuel system. I wrapped the fuel system with ceramic mat and foil. I opened up the lower cowling to allow airflow. The problem is solved. 98 degree weather no vaporization ever. Hot starts just fine. Hasn’t even thought about shutting down.
Before those mods I was terrified I was going to end my life on short final.
I posted videos of all this on YouTube. https://youtu.be/187jbCLdEoQ
N111YX wrote: Where one may be surprised, again only speaking from the experience of operating my airplane, is a relatively (compared to say a C-152 or Warrior ect.) high sink rate that develops about 15-20 mph above the stall speed.
Generally, in most airplanes we approach at 130% of the stall speed and bleed that extra 30% of speed during the flare to carry us safely to one inch off the ground at the stall speed (ideally). This value may not be applicable to your airplane.
I've found that if I use 1.3 X Vs, then excess power is almost always required to maintain my desired glidepath. Therefore, I have developed the following technique from experience.
My trick is to bug a speed on my EFIS airspeed indicator that I call the "minimum flare speed". It's a speed that is in essence the beginning of the "sink" range and guarantees adequate pitch control through touchdown. I will not mention that speed here because it will be different for every airplane because of many variables. You can find this speed by entering the flare at different speeds until no power is required to correct a mushy, sinking touchdown. I figure that if I ever have to perform an unscheduled power-off landing, I will use this speed as a safe maneuvering target. In fact, I use it on every landing. I don't look at any particular number on final but rather my margin above my "target" speed. Ideally, I'll be at 10 feet AGL at idle power on my target speed. Any faster and I'll needlessly float, any slower and the elevator authority will be too mushy.
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