Why do air traffic controllers use ICAO phonetics to pronounce numbers and letters?

Air traffic controllers use ICAO phonetics primarily to clarify and prevent misunderstandings during communications. Aviation operates in a high-stakes environment where any miscommunication can lead to serious consequences, including accidents. The phonetic alphabet ensures that letters and numbers are pronounced clearly and unambiguously, reducing the chances of misinterpretation, especially in situations where background noise might interfere with radio transmissions or when communications involve non-native English speakers. This standardized approach to communication helps maintain safety and efficiency in air traffic operations.

While making communication official, speeding up transmissions, or complying with legal requirements are relevant considerations in air traffic control, the main purpose of using ICAO phonetics is to enhance clarity and reduce the risk of errors in critical communications.