What is the consequence of having a runway heading more than 30º different from the final approach course?

When a runway heading is more than 30º different from the final approach course, it indicates that there is significant angular deviation between the intended flight path and the runway alignment. This situation often requires a non-standard suffix in the approach, which serves to alert pilots and air traffic control (ATC) that extra considerations or procedures may be necessary due to the misalignment.

A non-standard suffix may involve specific instructions that help ensure safety during the approach, especially concerning how the aircraft will be aligned with the runway upon landing. This becomes crucial because conventional instrument approaches are designed for smooth transitions, and significant heading discrepancies can complicate this transition, increasing the risk of misalignment during critical phases of flight.

Contextually, the reason other options may not apply would include that a standard approach isn't simply terminated based on a heading difference (a). Additionally, while low visibility conditions could factor into landing procedures, the presence of heading disparity alone does not assume low visibility (c). Finally, requesting a vector to final is not necessarily a requirement; it may depend on other operational factors and isn't strictly related to a heading discrepancy alone (d). Thus, the need for a non-standard suffix in the approach is the correct implication of significant runway heading deviation.