What does an X in the C4 space indicate?

What does an X in the C4 space indicate?

• A. EVRI (Exceptional Vertical Rate Indicator)
• B. Range error
• C. Altitude block error
• D. Missing timestamp

Answer: (A)

An X in the C4 space signals an exceptional vertical rate. It means the vertical speed value can’t be represented as a normal numeric value in the field, so the system uses EVRI, the Exceptional Vertical Rate Indicator, to flag that the rate is outside standard bounds and needs special interpretation. EVRI serves to alert you that the vertical rate data isn’t just a simple number and may require a specific handling or lookup to understand the actual rate. Other data issues—like a range error, an altitude block error, or a missing timestamp—are flagged differently in their respective fields, not by an X in the vertical-rate space.

An X in the C4 space signals an exceptional vertical rate. It means the vertical speed value can’t be represented as a normal numeric value in the field, so the system uses EVRI, the Exceptional Vertical Rate Indicator, to flag that the rate is outside standard bounds and needs special interpretation. EVRI serves to alert you that the vertical rate data isn’t just a simple number and may require a specific handling or lookup to understand the actual rate. Other data issues—like a range error, an altitude block error, or a missing timestamp—are flagged differently in their respective fields, not by an X in the vertical-rate space.