What is the correct phraseology to clear an aircraft whose route has not changed beyond a holding fix?

The phrase "VIA LAST ROUTING CLEARED" correctly conveys the necessary information that the aircraft is cleared to follow the last routing it received. In air traffic control communication, clarity and brevity are essential, which is why this phraseology is concise and directly relevant to the aircraft's situation.

The use of the word "VIA" implies that the aircraft will continue on the last route it was given, and "CLEARED" indicates that the air traffic controller affirms the clearance to maintain that routing. It avoids ambiguity, ensuring pilots understand they should follow the previously instructed path without any changes.

This phraseology is standard in air traffic control, particularly when an aircraft is cleared to follow a previously issued route without any updates. By stating it in this format, it maintains a clear line of communication between the controller and the flight crew, which is vital for safe and efficient operations.

Other choices, while attempting to convey a similar message, either lack clarity or deviate from the accepted phraseology used in aviation communications. Maintaining established phraseologies helps ensure that all parties involved have a mutual understanding of instructions and clearances.