What may happen if a transponder code is set incorrectly?

• A. The aircraft may not be tracked accurately on radar
• B. The pilot will be unable to communicate
• C. The aircraft will be rerouted automatically
• D. The controller will ignore the aircraft

Answer: (A)

When a transponder code is set incorrectly, it can lead to inaccurate tracking of the aircraft on radar. The transponder is essential for providing the radar system with an aircraft's identification and altitude information, among other data. If a pilot inputs an incorrect code, air traffic control may receive misleading information about the aircraft's position or even confuse it with another aircraft. This misidentification can compromise safety, as controllers rely heavily on accurate transponder information to manage air traffic effectively.

The other options do not accurately reflect the consequences of an incorrect transponder code. The ability to communicate is not directly affected by the transponder settings, so a pilot would still be able to communicate with air traffic control. Automatic rerouting of the aircraft does not occur solely because of a transponder code error; such an action typically requires explicit instructions from air traffic control based on airspace needs. Lastly, while air traffic controllers may have difficulty tracking an aircraft with an incorrect code, they would not simply ignore it. Instead, they would attempt to clarify the situation or identify the aircraft through other means.