Which of the following is one of the four op checks?

• A. Post-flight check
• B. In-flight check
• C. Prior to flight
• D. Prior to troubleshooting

Answer: (C)

Operational checks are the structured tests used to confirm that the aircraft’s systems will function correctly around flight. One of these checks is performed before any flight to verify readiness and proper configuration, ensuring that controls move as they should, instruments and avionics respond properly, and essential systems show the correct status before you take off. This preflight verification helps catch faults that could be dangerous during flight, such as incorrect flight control setup, a faulty instrument indication, or a leak in the fuel system.

In-flight checks are carried out during the flight to confirm ongoing system operation, and post-flight checks are done after landing to catch issues that may have appeared during the flight and to prepare the aircraft for the next flight. Prior to troubleshooting isn’t itself an operational check; it’s a diagnostic step used to identify where a fault might be, rather than a standard check of aircraft readiness.