Which display may show dashes during an uncommanded propeller feather scenario?

• A. Speed display
• B. Torque and Np displays
• C. Altitude display
• D. Fuel flow display

Answer: (B)

In an uncommanded propeller feather scenario, the torque and Np (propeller speed) displays are specifically designed to reflect changes in propeller pitch and performance. When a propeller feathers unintentionally, it may result in the loss of thrust and changes to the torque being produced by the engine. As the propeller blade angle adjusts to a feathered position, the Np display could also indicate a significant drop in propeller speed, often leading to dashes being shown on the display instead of a numerical value. This is a visual representation to indicate that the propeller is not operating within its normal range, as the system can no longer reliably measure or display the propeller's operational parameters.

The other displays, such as speed, altitude, and fuel flow, do not undergo the same kind of change during an uncommanded feathering event, mainly because they are less directly related to the specific condition of the propeller system. Therefore, they would not typically reflect dashes, making the displays for torque and Np the correct selection in this scenario.