If a message is long or requires writing, what should a controller do?

Choosing to warn the pilot before giving a long message or one that requires writing is a prudent practice in air traffic control. This approach sets the expectation that the communication may take some time, allowing the pilot to prepare for the information being conveyed. By issuing a warning, the controller ensures the pilot is attentive and ready to receive a potentially complex message, which could include critical flight safety information or instructions that require action.

This practice is important because long or detailed messages can lead to misunderstandings if the pilot is not adequately prepared. It acknowledges the possibility that the pilot will need to jot down information, which can be critical for follow-up actions or clearances.

In contrast, transmitting a long message immediately without any lead-in may surprise the pilot and hinder their ability to accurately capture the necessary details. Requesting a repeat from the pilot might be relevant in different contexts, but it does not address the need for proper notification beforehand. Omitting unnecessary information is also important in communication efficiency, but in the context of a long message, giving a prior warning is crucial for ensuring clarity and comprehension.