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Oct 18, 2018, 12:42 PM
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Mini-HowTo

Cirrus seperate ailerons: part 5


The remaining Modes are Thermal and Land. The Cirrus’s trailing edge camber can be set to about 3-5 degrees down to increase the camber and lower the thermal speed. Since the speed will be lower I would set 100 percent on the D/R menu. The elevator setting could be set on the TX and it will be remembered. I am usually in a turn when in a thermal so I put in a little more up elevator trim. When I roll out and go straight I may see pre stall porpoising so I take the trim out. Of course you can cheat and put SAFE Self Level ON when thermaling (or searching for a thermal). Purists will get upset but Cirrus is your model. When both ailerons and flaps are cambered down you are at greater risk for stall because there is no washout on the wing (like you will get in Landing Mode). So stalls can be dangerous unless you have about 100 feet or 10 seconds to recover. Here is my stall recovery procedure:

Go full power as this will put you into the Launch mode. Flaps and ailerons will retract intoa minimum wing drag configuration. The prop blast over the elevator will allow more pitch control. If Self Level is On the nose may be down and so up elevator will be applied automatically. If the stall has not been broken then apply down elevator and opposite rudder (if a spin or spiral is seen). Down elevator with prop thrust over the elevator will cause a dive and increase in airspeed where recovery is possible. Now this is theory and will be flight tested later but it’s based on what works on Apprentice, Timber, Valiant and AT6 Texan. Here is an actual stall/crash that took place over a small pond.

I was flying Cirrus with my good flying buddy who is VERY experienced but had no Cirrus experience with SAFE On.
Some how Cirrus entered a stall and then a spiral and then a slightly nose down spin. This took place in about 5 seconds. I moved my sticks and took immediate control at about 50 ft above the pond. With previous experience in the above SAFE models Self Level On will recover as the nose will drop from a proper CG and when flying speed is achieved the nose will pick up and a power off glide will take place. Well there was just not enough altitude or time for this to take place. In hindsight applying full power would most likely increase rudder and elevator effectiveness and the stall/spin recovery would take place. Cirrus hit the pond in about a 10-20 degree nose down attitude with wings level. The speed was low maybe 5-10 mph so very little damage occurred. The top motor cowl popped off and was seen floating along with little foam pieces from the lower nose section. A plastic aileron cover came off and sank. I had all controls and even motor. I tried to power back to the shore with the prop splashing all over but I had no rudder stearing as there is no sub rudder! Cirrus floated to the bank and somebody picked it up and put it on the grass. My buddy retrieved all the pieces about 40 minutes later and drained/dried off the components. That night I tried to bind but I got no solid RX light. The next day when she was completely dried off I was able to bind and everything worked except the nose gear/rudder servo had some limited travel because of gear damage. I replaced the rudder servo and have 5 flights so far with no problems. I’m carefull to not get into a stall or spin until I do testing at higher altitudes and different flight modes. I believe that the Landing Mode with reflexed ailerons (washout) and full flaps (Washout) will be the best mode for stall prevention and recovery. That will come with flight testing. In the Function List select Camber Presets and see the pics for preliminary settings.
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