When we designed the aural AOA logic, we mimicked the system McDonnell had in the F-4. The jet had a "pedal shaker" that functioned as stall warning--similar to stick shakers in modern airliners. The old pedal shaker was definitely attention getting. Every once in a while, you would miss judge a base turn and if you worked too hard to salvage a bad situation; you would end up on the pedal shaker. That was the jet's way of saying "hey dude, you are pulling too hard, and if you keep it up, this isn't going to end well."
Since it's not a good idea to bolt a shaker into an airplane with reversible flight controls, we use the high pulse rate warning to mimic the input that would be provided by the pedal/stick shaker.
Here's a short clip of a final overshoot right up to the maximum aerodynamic limit of the airplane. What's interesting is that when the airplane is deep on the back side of the power required curve, how long the it takes to get back to an ONSPEED (solid tone) condition. In other words, it wouldn't take much of a ham fist to botch a recovery in this condition. This recovery required an AOA reduction AND power to re-establish an ONSPEED condition. Because RV's have such good low-speed/high alpha handling characteristics, the airplane is solid with just a small amount of buffet. Without benefit of an accurate tone (or other energy warning system/display/etc.), it would be tough to realize how close the aerodynamic margin the airplane is. Obviously, this was a planned test--so no startle factor. Consider what would happen if you dropped airspeed out of the cross-check, didn't have the benefit of accurate energy cues or weren't coordinating rudder properly--this could definitely be a "square corner."
https://youtu.be/pslGHjISg1g
There is lots of radio chatter and intercom, so you can see how the tone is attenuated and blends in an operational environment. If you like flying formation--kind of handy to hear your AOA/energy state when your eyes are welded on lead.
Shameless plug: We'll be conducting a forum at OSH on Friday, 30 Jul at 0830 and we'll be around the Sunday Beer Tasting and Monday Social if you want to learn more about this or just talk energy management. We can even practice shooting down watches
Fly safe,
Vac
FlyONSPEED.org
Since it's not a good idea to bolt a shaker into an airplane with reversible flight controls, we use the high pulse rate warning to mimic the input that would be provided by the pedal/stick shaker.
Here's a short clip of a final overshoot right up to the maximum aerodynamic limit of the airplane. What's interesting is that when the airplane is deep on the back side of the power required curve, how long the it takes to get back to an ONSPEED (solid tone) condition. In other words, it wouldn't take much of a ham fist to botch a recovery in this condition. This recovery required an AOA reduction AND power to re-establish an ONSPEED condition. Because RV's have such good low-speed/high alpha handling characteristics, the airplane is solid with just a small amount of buffet. Without benefit of an accurate tone (or other energy warning system/display/etc.), it would be tough to realize how close the aerodynamic margin the airplane is. Obviously, this was a planned test--so no startle factor. Consider what would happen if you dropped airspeed out of the cross-check, didn't have the benefit of accurate energy cues or weren't coordinating rudder properly--this could definitely be a "square corner."
https://youtu.be/pslGHjISg1g
There is lots of radio chatter and intercom, so you can see how the tone is attenuated and blends in an operational environment. If you like flying formation--kind of handy to hear your AOA/energy state when your eyes are welded on lead.
Shameless plug: We'll be conducting a forum at OSH on Friday, 30 Jul at 0830 and we'll be around the Sunday Beer Tasting and Monday Social if you want to learn more about this or just talk energy management. We can even practice shooting down watches
Fly safe,
Vac
FlyONSPEED.org