Update VTOL.md

docs/VTOL.md

@@ -186,7 +186,8 @@ Add new servo mixer rules, and select 'Mixer Transition' in input. Set the weigh
 ## Motor 'Transition Mixing': Dedicated forward motor configuration
 In motor mixer set:
 - -2.0 < throttle < -1.0: The motor will spin regardless of the radio's throttle position at a speed of `abs(throttle) - 1` multiplied by throttle range only when Mixer Transition is activated.
-
+- Airmode type should be set to "STICK_CENTER". Airmode type must NOT be set to "THROTTLE_THRESHOLD". If set to throttle threshold the (-) motor will spin till throttle threshold is passed.
+  
 ![Alt text](Screenshots/mixerprofile_4puls1_mix.png)
 
 ## TailSitter 'Transition Mixing': 
@@ -233,4 +234,4 @@ If you set `mixer_automated_switch` to `OFF` for all mixer profiles (the default
     2. In addition to 1. Add a little yaw mixing(about 0.2) in tilt motors.
 - There will be a time window that tilting motors is providing up lift but rear motor isn't. Result in a sudden pitch raise on the entering of the mode. Use the max speed or faster speed in tiling servo to reduce the time window. OR lower the throttle on the entering of the FW mode to mitigate the effect.
 ## Dedicated forward motor 
-- Easiest way to setup a vtol. and efficiency can be improved by using different motor/prop for hover and forward flight
+- Easiest way to setup a vtol. and efficiency can be improved by using different motor/prop for hover and forward flight