Which NAVAID is used for nonprecision instrument approaches and may have a final approach course offset up to 3 degrees and wider than a localizer?

• A. Slant range
• B. Simplified directional facility
• C. Skin friction drag
• D. Slaved compass

Answer: (B)

This item tests recognizing a NAVAID that provides lateral guidance for nonprecision instrument approaches with a final approach course that can be offset from the runway and is wider than a localizer. The Simplified Directional Facility is designed for nonprecision approaches, giving you a final approach course without vertical guidance, and it can be offset up to about 3 degrees from the runway centerline while having a wider course path than a standard localizer. That combination—lateral guidance without vertical guidance, a wider course, and a small allowable offset—fits the Simplified Directional Facility.

The other options aren’t navigational aids used for instrument approaches: slant range is a distance measurement, a slaved compass is a heading instrument, and skin friction drag is an aerodynamic property.