When should NRP be removed from the flight plan remarks section?

The correct answer highlights that the Notice of Proposed Rulemaking (NRP) should be removed from the flight plan remarks section when the pilot specifically requests a change in route. This is because the NRP is primarily used to inform air traffic controllers and other relevant parties about specific operational restrictions or procedures that might affect the flight based on its initially filed route. If a pilot requests a route change, it signals a shift in the operational context that would require updating the flight plan. In such cases, the previously noted NRP may no longer be applicable or relevant for the new routing.

In contrast, keeping the NRP when in a holding pattern, when air traffic control changes, or once the aircraft reaches cruising altitude does not address the need for real-time adaptation of the flight plan based on the pilot's direct input regarding route adjustments. Since a request for a route modification alters the dynamics of the flight, it justifies the removal of the NRP to ensure the flight plan remains current and reflects the most accurate operational conditions.