What risk is posed by a blockage in the fuel tank vent?

A blockage in the fuel tank vent creates a situation where air cannot enter the tank to replace the fuel that is being used. As fuel is consumed during flight, a vacuum forms inside the tank because the space previously occupied by the fuel is no longer filled with air. This vacuum can lead to flow issues, affecting the ability of the fuel system to deliver fuel consistently to the engines. If the vacuum becomes strong enough, it can even prevent fuel from flowing at all, potentially leading to engine starvation and loss of power.

Understanding the significance of the fuel tank vent is crucial for maintaining proper fuel flow and ensuring engine performance. Proper venting is essential to allow for the equalization of pressure within the tank, which ensures that fuel can be drawn smoothly and efficiently without interruption.