What must be checked within 3 minutes to 2 hours after engine shutdown?

The requirement to check the engine oil level within 3 minutes to 2 hours after engine shutdown is critical for several reasons. First, checking the oil level soon after shutdown allows for a more accurate assessment of the oil level since the oil has not yet had the opportunity to drain back into the engine, which can lead to misleadingly low readings if checked too long after shutdown.

Maintaining the correct oil level is vital for engine performance and longevity, as it ensures that the engine components are adequately lubricated. Insufficient oil can lead to increased friction, overheating, and ultimately, engine damage. Hence, this action is not just a procedural check but a necessary maintenance practice to ensure the aircraft's safety and operational integrity.

Other options, while important for overall aircraft operations, do not carry this same immediacy and critical nature after engine shutdown. For instance, checking engine temperature is typically done during operations rather than shortly after shutdown, and fuel tank levels can be assessed at different intervals based on flight operation. Cargo compartment pressure, while essential for safety, is also not specifically tied to the short window following engine shutdown.