Radio Setup - Failsafe
last updated 12-1-2006

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What is Failsafe?
This is a feature available when you use a PCM receiver. The function of failsafe is to lock the servos in a certain position in the event the receiver loses the signal from the radio. Most PCM receivers will also enter failsafe mode if the battery voltage gets too low.
So what would be the reason for the receiver to lose the signal? This is most often caused by a loose bolt. A bolt that is vibrating against metal or carbon, metal vibrating against other metal, metal to carbon, or carbon to carbon will generate a radio signal. When the receiver picks up both the signal from the radio as well as the one generated from the vibrating pieces it will enter failsafe mode.
So what position do the servos go to when the receiver goes into failsafe? The radio will have a failsafe menu function that allows you to decide what the servos should do. The most common setup is to have all but the throttle channel hold on the last good signal received. The throttle however is set to go to an idle. The reason is that if the engine goes to an idle that means there is less vibration in the helicopter and hopefully the loose piece will stop making radio noise or at least change to a different frequency and return control back to you. And in the event the radio interference is external (such as someone turning on their radio on your channel) then at least with the throttle at idle the helicopter will not fly away as well as decrease the chance of more damage since the engine will not be turning the blades.
When the radio goes to failsafe does it remain there? Only until the interference goes away. Often times when there is a problem you will hear the throttle cut to idle then a second later return. It may does this a few times throughout the flight. Anytime you hear the throttle cut out you should immediately land and try to find out what happened. Don't just continue to fly as the interference could become bad enough that the receiver remains in failsafe long enough to cause a crash.
Setup:
Airtronics RD6000/RD8000 - Press the right/left arrow to get to 'Th' then go down to 'Fail'. With the throttle stick all the way down then press 'Yes/Inc+'. Leave the other channels set to 'Inh'.

Futaba 7C - In the Basic menu go to [F/S] - For all channels except 3, set them to 'NOR'. For channel 3 (throttle) set it to 'F/S' and with the throttle stick all the way down hold the center of the jog will for one second. You will see a percentage show up across from the throttle channel.

Futaba 9C - In the basic menu go to [F/S] - For all channels except throttle, set them to 'NOR'. For throttle set it to 'F/S' and with the throttle stick all the way down hold the center of the jog will for one second. You will see a percentage show up across from the throttle channel.

JR 6102 - In the menu select 'Fail Safe'. For all channels except 'TH' set them to 'HLD'. Select 'TH' if it has 'HLD' the use the + or - buttons to change it to a line. With the throttle stick all the way down press the 'clear' button. This will set the failsafe position for idle.

JR 9303 - Press the List button then select [Fail Safe]. For all channels except 'THR' set them to 'HOLD'. Set 'THR' to 'F.S.' With the throttle stick all the way down press the 'CLR' button.