What is the upper altitude limit for the Mustang working area?

The correct answer reflects the established upper altitude limit for the Mustang working area, which is set at 17,500 feet Mean Sea Level (MSL). This altitude is significant as it is aligned with the operational guidelines and safety parameters that define the airspace usage for various activities, including training exercises and missions. Understanding this limit is crucial for ensuring compliance with air traffic regulations and maintaining safe operations within the designated airspace. The choice of 17,500 feet allows adequate vertical separation from other air traffic and statutory airspace boundaries, facilitating effective management of aircraft operations in this sector.