Which component directly shuts off fuel during NP overspeed?

Which component directly shuts off fuel during NP overspeed?

• A. PCL
• B. LDS
• C. DEC
• D. ODV

Answer: (D)

The key idea is that during NP overspeed, the system needs an immediate, automatic action to stop fuel to the engine. That action is performed by the Overspeed Disconnect Valve, a dedicated fuel shutoff device that closes when an overspeed signal is detected. This directly blocks fuel flow so the engine cannot accelerate further, protecting the turbine from damage. The pilot’s PCL only sets the requested power and does not automatically cut fuel in an overspeed event, while the Digital Electronic Control (DEC) and related control subsystems modulate fuel under normal operation but do not provide the instantaneous shutoff that the overspeed disconnect valve delivers.

The key idea is that during NP overspeed, the system needs an immediate, automatic action to stop fuel to the engine. That action is performed by the Overspeed Disconnect Valve, a dedicated fuel shutoff device that closes when an overspeed signal is detected. This directly blocks fuel flow so the engine cannot accelerate further, protecting the turbine from damage. The pilot’s PCL only sets the requested power and does not automatically cut fuel in an overspeed event, while the Digital Electronic Control (DEC) and related control subsystems modulate fuel under normal operation but do not provide the instantaneous shutoff that the overspeed disconnect valve delivers.