Which of the following is NOT a TR test situation?

• A. After maintenance of any type
• B. First flight of the day
• C. When the flight ahead is predicated on their use for performance
• D. Before taxi

Answer: (D)

TR tests are used to verify that critical systems are ready for flight when their performance could affect the operation. They’re triggered in situations where the system has just undergone maintenance, after downtime before the day’s operations, or when the performance of a following flight depends on that system being proven good. In these contexts, re-checking the system ensures it meets specifications before it’s relied upon for flight.

Starting a test before taxi isn’t part of this testing pattern. Before taxi is a ground/preflight phase focused on standard checks and readiness to move, not on validating a system’s performance under flight conditions. Therefore, it isn’t treated as a TR test situation.