Certified Flight Instructor (CFI) Practice Exam

In a METAR report, the letter "U" signifies that the weather condition is "Unknown." This designation is used to indicate that there is no available or applicable information for a specific parameter. For example, if a specific aspect of the weather cannot be determined or reported due to observational limitations, "U" will be used to communicate this uncertainty. Understanding METAR reports is vital for pilots, as it provides critical information about current weather conditions at airports. Each component of the report has specific meanings, and knowing how to interpret certain symbols and letters, such as "U," helps in making informed decisions regarding flight safety. The other interpretations, while plausible in other contexts, do not apply to METAR reports. Options like "Unstable," "Urgent," and "Unclear" do not reflect established aviation terminology regarding weather conditions as presented in METARs, which maintain a standardized format for clarity and safety in aviation operations.