Which of the following occurrences requires immediate notification of the NTSB according to NTSB Part 830?

The requirement for immediate notification of the National Transportation Safety Board (NTSB) arises from occurrences involving significant damage caused to property other than the aircraft itself, specifically when this damage exceeds $25,000. This threshold is significant since it indicates a serious incident that may have broader implications for public safety and regulatory oversight.

According to NTSB regulations, the focus on damage that exceeds this amount addresses concerns regarding the potential for accidents that could impact people and infrastructure outside of the aircraft. Events causing substantial property damage warrant investigation to determine the factors contributing to the incident, which can be crucial in preventing future occurrences.

While injuries to passengers and damage to the aircraft itself are certainly critical matters that require reporting, the NTSB's criteria for immediate notification highlights the potential risks associated with significant damage to external property. In contrast, flight cancellations due to weather do not pose inherent safety issues in the same context and do not trigger the need for such immediate reporting to the NTSB.