What is the minimum distance to consider when issuing an ALNOT for an aircraft?

The correct answer is based on established protocols for search and rescue operations. When issuing an Alert Notice (ALNOT) for an aircraft, it is standard practice to consider a minimum distance of 50 miles on either side of the aircraft's last known route. This distance is deemed sufficient to ensure that search efforts can account for possible deviations from the planned route due to various factors, such as changes in flight path, emergencies, or navigational errors.

Setting the minimum distance to 50 miles effectively balances the need for a thorough search area while still being manageable within the resources available for the search operation. This approach helps to maximize the chances of locating the aircraft or determining its last known position, which is critical in ensuring the safety of the crew and passengers.

While other options suggest larger distances, 50 miles has been determined to be the optimal range necessary for effective search and rescue without unnecessarily overextending resources. Therefore, this choice aligns with the established guidelines and best practices in aviation safety and response.