I am probably like most people who fail to read manuals. They always end up in the bottom of a drawer some place never to be found. Luckily, I had nothing to do one day and decided to read my GY 401 manual. It has an idiosyncrasy not found in any other gyro I have used. When first turning on the power to your radio gear, you must have your transmitter turned on and have the gyro mode set to heading hold. You must also make sure your rudder trim lever is centered and make sure you do not move the rudder stick.

These precautions must be followed because this gyro stores the neutral value of the rudder channel each time the gyro is powered. It only stores these values when turned on in heading hold mode. When the power is turned on in normal mode the indicator LED on the unit flashes an alarm code. If you fail to follow these procedures you can still save the neutral settings by switching between heading hold mode and normal mode very quickly. Three times within one second is required. This tells the gyro to store the current rudder input as the neutral position.

One other nice feature is re-centering of the tail in heading hold mode. When walking the machine to the flight line in heading hold mode, the tail will drift to one extreme. Centering the tail is always a good practice as it puts less load on the tail drive and engine during spool up. You can center the tail the traditional way of switching to normal and then back to heading hold. But, for those people who may not have the gyro mode tied to a switch, you can perform the same function by wiggling the rudder left and right very quickly. Again, three times within one second is required.