What is the primary purpose of Instrument Flight Rules (IFR)?

The primary purpose of Instrument Flight Rules (IFR) is to guide pilots during poor visibility conditions. IFR establishes the procedures and regulations necessary for flying an aircraft when visual reference to the ground or other landmarks is insufficient. This often occurs in scenarios involving cloud cover, fog, rain, or other weather phenomena that obstruct a pilot's ability to see outside the cockpit.

By following IFR procedures, pilots rely on instruments to navigate, communicate, and maintain safe separation from other aircraft. This framework ensures that pilots can operate safely even when visual cues are limited. Therefore, IFR is fundamental for managing flights in a controlled and systematic manner when the weather conditions would otherwise pose significant challenges to visual navigation.

In contrast, other choices focus on situations not aligned with the primary intent of IFR. Regulating flight during clear skies and specifying conditions for visual flying are related to Visual Flight Rules (VFR), which applies when conditions are favorable. Reducing aircraft noise during night flights pertains to noise abatement procedures, rather than navigation and safety under poor visibility.