Final answer:
When the airfield is open and during mandatory augmentation of AMOS, various activities such as regular airfield operations, security measures, drills, and training exercises may be conducted.
Step-by-step explanation:
In the context of the question, when the airfield is open and during periods when any of the mandatory augmentation of AMOS is required in accordance with Chapter 3, several activities may be conducted. These activities include regular airfield operations such as takeoff and landing of aircraft, refueling, maintenance, inspections, and traffic control. Additionally, during mandatory augmentation of AMOS, additional activities may be conducted such as increased security measures, emergency response drills, or training exercises.