What heading should an aircraft be at to intercept the localizer course if the published ILS front course is 300° and the aircraft is heading 255°?

For an aircraft to intercept the localizer course when the published Instrument Landing System (ILS) front course is 300°, it should adjust its heading to match this course. The localizer provides lateral guidance to help the aircraft align with the runway's centerline.

In this scenario, the aircraft is currently heading 255°. To effectively intercept the localizer and align with the 300° course, it needs to make a turn towards the localizer's direction—specifically, to 300°. This brings the aircraft onto the correct approach path for landing.

Maintaining a heading of 255° would keep the aircraft away from the desired localizer course, making it impossible to intercept. Turning to 255° would not bring the aircraft closer to the 300° course but would actually maintain the current course, which is ineffective for intercepting the localizer. Lastly, turning to 270° would result in a heading that does not align with the approach course, moving the aircraft further west rather than on track for the 300° course.

Thus, the correct action is to turn to 300°, directly aligning with the ILS course and allowing the aircraft to intercept and follow the localizer approach properly.