In which scenario is permission required for glider operations?

Glider operations near controlled airspace, such as Class B, C, D, or E, require permission from Air Traffic Control (ATC) due to the complexities and potential conflicts with other aircraft in these busy environments. Controlled airspace is designated for safe and efficient management of air traffic, and gliders, which operate at slower speeds and can be more unpredictable due to their flight characteristics, must obtain clearance to ensure safety.

In contrast, the other scenarios listed typically do not require permission in the same stringent manner. While night flying and operations during inclement weather have their own regulations and safety considerations, they do not necessarily require prior permission from ATC. Similarly, crossing state lines does not inherently involve airspace that requires permission, as long as the flight remains outside controlled airspace. Thus, obtaining clearance while operating near specifically defined airspace is an essential regulatory requirement to promote safety and order in aviation operations.