What is the purpose of a belt clutch in the drive system?
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A
It allows the displacement of the ignition timing during start-up.
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B
It connects or disconnects the transmission from the engine to the main rotor gearbox.
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C
It prevents blade movements in gusty wind conditions by blocking the drive shaft.
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D
It prevents the mechanical blocking of the main rotor during autorotation.
Refer to figure.
Some helicopters use a “belt drive” to transmit power from the engine to the transmission. A “belt drive” consists of a lower pulley attached to the engine, an upper pulley attached to the transmission input shaft, a belt or a set of V-belts, and some means of applying tension to the belts. The belts fit loosely over the upper and lower pulley when there is no tension on the belts.
Some aircraft use a clutch for starting. This allows the engine to be started without requiring power to turn the transmission. One advantage this concept has is that without a load on the engine starting may be accomplished with minimal throttle application. However, caution should also be used during starting, since rapid or large throttle inputs may cause overspeeds.
Once the engine is running, tension on the belts is gradually increased. When the rotor and engine tachometer needles are superimposed, the rotor and the engine are synchronised, and the clutch is then fully engaged.
The purpose of a belt clutch in the drive system is to connect or disconnect the transmission from the engine to the main rotor gearbox.
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Austro Control