What triggers the L/R WING TANK OV PRESS annunciator?

The L/R WING TANK OV PRESS annunciator is triggered specifically when the pressure differential in the wing fuel tank exceeds a threshold of greater than 3.5 +/- 0.5 psi. This pressure differential is crucial for proper fuel management and ensures that the fuel system operates within safe limits. If the differential is too high, it may indicate a potential fault in the fuel system, including the possibility of a blocked vent or malfunctioning fuel system components that can lead to dangerous overpressure conditions.

Understanding this trigger is vital for pilots and maintenance personnel, as it helps in monitoring the health of the aircraft’s fuel system. Conversely, factors like the fuel tank being empty, fuel temperature exceeding limits, or a clogged fuel filter do not directly relate to the overpressure condition in the tanks, thus they do not activate the L/R WING TANK OV PRESS warning. This distinction emphasizes the importance of monitoring pressure levels specifically for the safe operation of the fuel system.