Two displays and one position source
A fictional controller-training system presents two position labels for the same aircraft. Both ultimately use the same simulated onboard navigation source, although they appear in different windows. The exercise deliberately inserts a shared position offset and both labels continue to agree. A trainee calls their agreement independent confirmation that the aircraft is correctly located. Another asks which observations genuinely have a different dependency. The task does not identify an approved real surveillance configuration, authorize a fallback mode or supply an identification tolerance. It asks for analysis of the source architecture and the evidence that remains missing. A correct answer distinguishes visual duplication from independent measurement and avoids inferring operational serviceability merely because a label is stable and easy to read.
1. Why is the agreement insufficient?
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Both displays depend on the same deliberately offset source. Agreement can reproduce a shared error and is not an independent position confirmation.
2. What further evidence would be relevant?
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The actual approved independent observations, source integrity and applicable system procedures would be needed. The exercise alone cannot establish identification or authorize a surveillance minimum.