What is the expected procedure for takeoff times on Runway 31?

The expected procedure for takeoff times on Runway 31 is designed to ensure that operations are conducted efficiently and safely. When considering the timeline provided, 15 minutes prior and 5 minutes prior to takeoff allows for a structured yet flexible approach to ground operations and final preparations. The inclusion of -30 minutes, while unconventional, can imply that there is also an allowance for early notifications or adjustments that need to take place well in advance of the actual takeoff time.

This option emphasizes a progressive timeline that accommodates preparations and checks necessary for a safe departure, reflecting a comprehensive understanding of protocol. Other choices either do not align with standard practices or fail to incorporate timings that provide adequate buffers or preparations required prior to takeoff. The correct answer optimally balances these factors, which is crucial for maintaining safety and efficiency in flight operations.