Spektrum SPMMSJR9 - Manual (Page 20)

Spektrum Air Module 0
All of Spektrum’s aircraft receivers feature a unique SmartSafe fail-safe system,
while the AR 9000 features two types of fail-safe: SmartSafe and preset fail-safe.
SmartSafe
This type of fail-safe is especially ideal for most types of electric aircraft and is also
recommended for most types of gas- and glow-powered airplanes and helicopters.
Here’s how SmartSafe works.
Receiver Power Only
When the receiver only is turned on (no transmitter signal is present), all servos
except for the throttle are driven to their preset fail-safe positions, normally control
surfaces at neutral and the landing gear down. These fail-safe positions are stored
in the receiver during binding. At this time the throttle channel has no output, to
avoid operating or arming the electronic speed control. In glow-powered models,
the throttle servo has no input so it remains in its current position.
After Connection
When the transmitter is turned on and after the receiver connects to the transmitter,
normal control of all channels occurs. After the system makes a connection, if
loss of signal occurs SmartSafe drives the throttle servo only to its preset fail-safe
position (low throttle) that was set during binding. All other channels hold their
last position. When the signal is regained, the system immediately (less than 4 ms)
regains control.
Fail-Safe Functions