Simplified directional facility (SDF)


A NAVAID used for nonprecision instrument approaches. The final approach course is similar to that of an ILS localizer; however, the SDF course may be offset from the runway, generally not more than 3°, and the course may be wider than the localizer, resulting in a lower degree of accuracy.

Source: Pilot Handbook of Aeronatical Knowledge

Refer to:

  • AIM