RE: Which Aeroplane Gyros are best?
I use the Futaba 401 on rudder for takeoff on tail draggers and some times for landing. Some tips:
1. Put the gyro on a 2 or 3 position switch. Up is for heading hold mode (AVCS) 70% gain which is used ONLY on takeoff.
2. Down switch turns the gyro off (actually it is rate mode with about 3% gain).
3. If a 3 position switch, I use the middle position for rate mode at 40% gain to control gound loops on landing.
Note that the gyro must be switched off as soon as the plane leaves the ground otherwise you will not be able to contol the plane in the air. Also while in HH mode, do not move the rudder stick because you will get unexpected direction changes. I use a p-mix to blank the rudder control when in HH mode.
The procedure I follow in flying the plane is.
1. Turn the transmitter on with the switch set to HH mode.
2. Turn the receiver on allowing the gyro to initialize.
3. Turn the gyro off to taxi the plane out and line it up for takeoff.
4. Flick the gyro gain control switch three times leaving it in HH mode. This sets the gyro in the correct direction for takeoff.
5. Apply power. When the plane reaches take off speed, pull back on the elevator AND TURN OFF THE GYRO.
6. Fly with the gyro off.
7. When on the landing approach, you can turn the gyro back on in rate mode 40% (middle switch position) for handling cross winds and ground loops.
This approach has been working very well for me on six tail draggers for the past year. Some people do not use HH mode on takeoff for safety reasons but use high gain rate mode. This too can work well. I just prefer HH mode on take off.
Bruce