What minimum visibility is required during the night for non-mountainous local weather when using NVGs or TAWS?

The minimum visibility required during the night for non-mountainous local weather when using Night Vision Goggles (NVGs) or Terrain Awareness and Warning Systems (TAWS) is indeed set at 3 miles. This standard is put in place to ensure that flight crews have adequate visual reference for navigation and obstacle awareness, even when operating in darkness.

Utilizing NVGs can enhance visibility, allowing for improved situational awareness. However, the 3-mile visibility requirement serves as a safety threshold to account for the limitations of night vision equipment and to support safe operation under various environmental conditions. At this level of visibility, crew members can effectively utilize their tools to maintain safe flight operations while minimizing risks associated with low-light environments, such as terrain awareness or the potential for mid-air collisions.

Setting the requirement at this specific distance balances operational need with safety, allowing crew members to make informed decisions while navigating in conditions that are inherently more challenging than during daylight operations. As such, adhering to this visibility standard is critical for ensuring the safety of patients, crew, and the aircraft during nighttime operations.