FUTABA 12K Instruction Manual page 14

Self neutral type（This transmitter）
A throttle stick returns
neutrally by a spring.
WARNING
You cannot use the throttle stick of self-neutral type for RC airplane, RC helicopter, and
certain multi-copter.
It's very dangerous if Engine / Motor becomes middle-speed by self-return.
It's necessary to change the stick to the ratchet type if using it for RC airplane and RC
helicopter.
Power ON
（Warning）
Throttle stick, to the bottom.
14 <Before Use>
Throttle stick warning
Throttle stick position warning
Alarm ！
Ratchet type（General transmitter）
A throttle stick
doesn't return
neutrally.
Throttle stick：
Motor or engine power is controlled.
Release of the throttle position warning
LINKAGE MENU 2/2 ⇒ WARNING ⇒ THR POS. ⇒ OFF
WARNING
When it's use by RC airplane or RC helicopter,
turn on a throttle positional warning.