When is a profile B check required?

A profile B check is specifically mandated after significant maintenance procedures, such as dual engine removal or any engine-related changes. This check is designed to ensure that the aircraft is still functioning correctly and safely after such critical work has been performed. It involves thoroughly inspecting the aircraft systems and components that may have been affected during the engine-related maintenance.

When engines are removed and replaced, the surrounding systems can have implications for safety and operational readiness. Therefore, confirming that everything is in optimal condition before the aircraft is returned to flight status is essential. This diligent approach helps prevent potential issues that could arise from inadequate verification of engine-related work.

The other options refer to situations requiring checks or inspections of varying types, but they do not specifically align with the unique checks mandated after engine removals or modifications, which is why they do not apply in the context of when a profile B check is required.