What part of IFR flight is primarily affected by the DME readings?

The distance measuring equipment (DME) readings are primarily concerned with providing the pilot with accurate distance information to navigational aids (NAVAIDs). DME operates by sending signals from the aircraft to the ground station and measuring the time it takes for those signals to return. This information is crucial for navigation, allowing pilots to determine how far they are from a specific NAVAID, such as a VOR or an ILS facility.

Knowing the distance to navigational aids helps pilots maintain situational awareness and aids in planning approaches, holding patterns, and en route navigation. While altitude maintenance, flight path curvature, and vertical speed are important aspects of IFR flight, they are not directly influenced by DME readings. Those elements relate more to the aircraft's performance and trajectory rather than the distance to navigational aids, making the connection to DME readings particularly relevant in navigation contexts.