Most senior CFIs have at least one story of forcibly taking over control of an aircraft from a locked-up, panicked learner. A SAFE survey of CFIs revealed that 65% had at some point forcibly taken back aircraft control from an irrational student! One CFI/DPE revealed a crash where he struggled and lost this battle resulting in a dramatic crash. A person overcome by fear becomes a powerful and irrational animal in your cockpit. Step one is to avoid ever scaring your student. Step two is staying ever vigilant and be prepared in case this does happen.
The grieving father of a young female CFI who died in a dual accident shared his story and inspired several SAFEblogs on this topic. Unfortunately, new “millennial flight schools” tend to be all excitement and hope with the new growth in aviation. They never cover or train this dark side of the CFI profession. Please watch this recent Air Safety Institute”early analysis” dissecting a recent instructional accident and share it with other CFIs.The possibility of student lock-up is real, and probably more common than currently recognized. (Recent KSMO accident?)
If you are a solo pilot, the other side of this same fear equation is surviving startle. Panic is possible for anyone when exposed to a new and shocking flight experience outside their comfort zone. Self-calming is an important first step to regaining control. Every pilot should practice specific techniques like deep 
