If Mode C fails between 100 and 180, what is the first action required?

In the event of a Mode C failure between altitudes of 100 and 180, the first action required is to advise a manager and verbally coordinate with the next controller. This step is crucial as it ensures that the situation is properly communicated and managed at a higher level to maintain air traffic safety and efficiency. By informing a manager, you can get guidance on how to best handle the issue, and coordinating with the next controller ensures that they are aware of the failure and can take appropriate actions or precautions.

Establishing effective communication among the controllers is essential in managing airspace, especially when there is a failure in altitude reporting systems. It allows for a coordinated response, ensuring that all parties involved have the same information and can adjust their plans accordingly to address the potential risk posed by the Mode C failure.