🔍 Key Concepts

• How DME (Distance Measuring Equipment) calculates distance between an aircraft and a ground station • The meaning of slant range versus horizontal ground distance • The difference between DME distance and signals used for glide slope and localizer in an ILS (Instrument Landing System)

💭 Think About

• Is the distance measured by DME purely horizontal over the ground, or is it along the straight line between aircraft and station? • Which option describes a line-of-sight distance from aircraft to station, regardless of altitude? • Which choices are clearly related to Instrument Landing System (ILS) lateral/vertical guidance rather than distance measuring?

✅ Before You Answer

• Identify which answer choice refers specifically to line-of-sight distance between two points in 3D space • Eliminate any options that describe angles or course guidance instead of distance • Confirm that the remaining term is the standard aviation phrase used with DME distance in IFR training materials