If multiple targets are within the same IFF beam of the challenged track and only one aircraft responded, what IFF response is displayed on TRK AMP DATA?

• A. Valid
• B. Invalid
• C. Valid, invalid or ambiguous
• D. Ambiguous

Answer: (C)

When more than one target sits in the same IFF interrogation beam for a challenged track, the system can’t be certain which specific target generated the reply. That uncertainty means the IFF status shown on TRK AMP DATA isn’t fixed to just valid or invalid; it can reflect any of the possible outcomes depending on what the responder did and how the system associates the reply to the tracked target. If the responding aircraft sent the correct, verifiable IFF code, it’s considered valid; if the reply is not the expected code, it’s invalid; and if the system can’t confidently map the reply to a single target within the beam, it’s ambiguous. Since multiple targets in the beam introduce this ambiguity, the display can be valid, invalid, or ambiguous.