An approach guidance method for an airborne mobile platform, for example an aircraft, and associated system. The method includes determining a radius of a capture arc tangential to a glide slope, determining an altitude for tangentially intercepting the capture arc, and guiding the mobile platform to an intercept point on the capture arc. The glide slope is associated with a waypoint, and the radius of the capture arc depends on variable mobile platform speed. The altitude for intercepting the capture arc depends on the radius of the capture arc and on variable flight angle.