Call sign

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Call Signs in Aviation

Call signs are unique identifiers used by Air Traffic Control (ATC) to distinguish one flight from another. Although flight numbers are also assigned, call signs serve as a more precise means of communication due to their distinctiveness. Call signs can differ from flight numbers in two ways: firstly, some airline radio call signs might be different from the airline’s official name. This could be due to historical reasons or to ensure better clarity and brevity over the radio. Secondly, alphanumeric call signs have been introduced in recent years to prevent call sign confusion.

For instance, the flight number British Airways 123 might utilize the call sign Speedbird 1PW, where “Speedbird” is the radio call sign and “1PW” is the alphanumeric call sign. This approach helps avoid ambiguity over the radio, where multiple British Airways flights with similar numbers might be communicating with the same ATC. Similarly, charter and private flights might use call signs that are distinct from their assigned flight numbers. The aim is to ensure adequate and accurate communication between pilots and ATC for the safety of all flight operations.

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