Plain English Meaning

RNAV that uses a VOR/DME station to figure out where the airplane is will only be as accurate as that station and its signals. Small errors in the bearing, the distance, or the math the box does to combine them all add up and shift the airplane's computed position away from where it actually is.

Full Definition

The combined inaccuracies that affect a VOR/DME-based area navigation (RNAV) position solution. Because a VOR/DME RNAV computer derives the aircraft's position from a single VOR/DME station's bearing and slant-range distance, any error in the VOR signal, the DME signal, the airborne receiver, the computer, or the geometry between aircraft and station is carried into the computed position and the resulting .