What type of aircraft operation would benefit significantly from an FMS?

The operation that would benefit significantly from a Flight Management System (FMS) is long-haul flights with complex routes. An FMS is designed to simplify navigation and improve the efficiency of flight operations by automating tasks. For long-haul operations that often involve intricate flight paths, multiple waypoints, and changes in altitudes, the FMS provides extensive capabilities such as route optimization, fuel management, and performance calculations.

During these flights, pilots can rely on the FMS to assist with navigation throughout various phases, including enroute navigation and approaches, allowing them to focus on other critical flight management tasks. The FMS streamlines the process by providing guidance for maintaining precise flight paths, which is essential when operating over long distances with many navigational complexities.

In contrast, other forms of operation noted in the options, such as emergency landings, short-range flights with few waypoints, and visual flight rules (VFR) operations, typically do not require the sophisticated features that an FMS offers. Emergency scenarios are usually time-sensitive and require immediate manual control, while short-range flights and VFR operations often involve simpler navigation that doesn't necessitate the advanced functionalities of a full flight management system.