What is the function of the over-pressure burst disk in the vent surge and inner wing tank?

The over-pressure burst disk in the vent surge and inner wing tank serves a critical safety function by rupturing when the internal and external pressure differential exceeds a predetermined level. This design prevents excessive pressure build-up within the fuel tank, which could lead to structural failure or other hazardous conditions. By ensuring that pressure does not exceed safe limits, the burst disk effectively protects the integrity of the fuel system and the aircraft as a whole while allowing for safe fuel expansion and contraction due to temperature changes.

This mechanism is essential in maintaining the aircraft's operational safety, as excessive pressure could lead to disastrous consequences. In contrast, options related to contamination of the fuel system or structural integrity would not accurately describe the primary function of the burst disk, which is focused on managing pressure differentials rather than causing damage. Similarly, a burst disk leaking fuel onto the ground does not align with its intended purpose, which is to release pressure safely rather than allowing fluid to escape unintentionally.