Which of the following is NOT a type of op check?

• A. Prior to flight
• B. After engine shutdown
• C. Following a flight
• D. Prior to troubleshooting

Answer: (B)

Operational checks verify that systems function at specific points in the cycle after maintenance or use. Preflight checks, post-flight checks, and checks after engine shutdown are all aimed at confirming readiness and safe operation during different phases of flight or after operation. They are about confirming behavior, not diagnosing faults. Doing checks before you start troubleshooting isn’t an op check—it’s a diagnostic step. Troubleshooting comes first to identify issues, then op checks verify that the fixes or conditions are working as intended. So the statement describing checks prior to troubleshooting is not a type of op check.