Which steps constitute the proper procedure to perform a functional test on a radar altimeter?

Which steps constitute the proper procedure to perform a functional test on a radar altimeter?

• A. All of the above and check fail-safes
• B. Verify power and connect test equipment
• C. Perform range/ground reference checks
• D. Compare indicated altitude with known altitude

Answer: (A)

A comprehensive functional test for a radar altimeter must cover power and test setup, range performance, absolute accuracy, and fault handling to ensure the unit behaves safely and accurately in real conditions. Starting with power and connecting the test equipment ensures the instrument is operating from a proper supply and that all test signals are routed correctly, so subsequent measurements are valid. Then performing range and ground reference checks verifies the altimeter responds correctly across the expected measurement span and against known ground references, assessing linearity, range limits, and response characteristics. Next, comparing the indicated altitude with a known altitude confirms that the displayed value matches reality within tolerance, establishing true accuracy. Finally, testing fail-safes ensures that, if a fault occurs—such as a signal loss or out-of-range reading—the system responds with appropriate alarms or safe behavior to prevent misleading information from affecting flight operations. Because this broader approach combines power verification, measurement accuracy, reference validation, and fault protection, all these steps belong in the proper procedure.

A comprehensive functional test for a radar altimeter must cover power and test setup, range performance, absolute accuracy, and fault handling to ensure the unit behaves safely and accurately in real conditions. Starting with power and connecting the test equipment ensures the instrument is operating from a proper supply and that all test signals are routed correctly, so subsequent measurements are valid. Then performing range and ground reference checks verifies the altimeter responds correctly across the expected measurement span and against known ground references, assessing linearity, range limits, and response characteristics. Next, comparing the indicated altitude with a known altitude confirms that the displayed value matches reality within tolerance, establishing true accuracy. Finally, testing fail-safes ensures that, if a fault occurs—such as a signal loss or out-of-range reading—the system responds with appropriate alarms or safe behavior to prevent misleading information from affecting flight operations. Because this broader approach combines power verification, measurement accuracy, reference validation, and fault protection, all these steps belong in the proper procedure.