Specifications

Throttle Hold (switch)
A switch used to force a zero throttle setting regardless of the throttle stick position or idle-
up switch position. This is useful as a safety feature when connecting or disconnecting the
battery and also to quickly kill the motor when a helicopter crash is imminent.
Throw a Blade
A slang term describing a main rotor blade detaching from the rotor head and being flung
at high speed. This is very, very dangerous.
TL Translational Lift
The extra lift produced by the main rotor when a helicopter is moving horizontally or when
hovering in windy conditions. When a helicopter stops moving horizontally it tends to drop,
because it loses the extra lift.
TR
Tail rotor
Tractor tail rotor
A tail rotor that pulls air towards the tail boom. The Hummingbird Elite series uses a tractor
tail rotor.
See also Pusher tail rotor
Trickle Charge
A continuous charge rate of C/20. This is a safe level for continuous charging of NiCd
cells. Cells of other types, such as NiMH and Lipo should NOT be trickle charged.
Tracking
The path of a rotor blade as it spins. See also Section 13.6.1, “Blade tracking - CP heli-
copters”
Training Gear
A landing gear with a wider stance so the likelihood of tipping the helicopter on takeoff or
landing is reduced. Often used by beginners while learning to hover and they typically are
made of two crossing sticks with whiffle balls on the ends.
Transitional Lift
A corrupted form of translational lift.
See TL Translational Lift
Tx
Abbreviation for Transmitter
See also Rx
W
Washout
For a rotor blade, this references the area of the rotor blade where the leading edge has
less pitch than the trailing edge. Also, the collective pitch compensator is sometimes refer-
enced as a "washout unit".
See also Collective Pitch Compensator
Weathervane
The tendency of the helicopter to point into the wind like a windsock. The amount of
Glossary
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