Which combination triggers the stab trim warning clacker?

• A. LOW rate for more than 3 seconds
• B. MED rate for 2 seconds
• C. HIGH/3 seconds
• D. HIGH rate for more than 5 seconds

Answer: (C)

The warning clacker is designed to alert you to a potential trim runaway or fault by watching how quickly the stabilizer trim moves and for how long that rapid movement lasts. The system signals when the stabilizer is commanded to move at a high rate and that high-rate movement continues for a short, defined period. Among the given options, only a high-rate command lasting about three seconds meets that threshold, so it triggers the audible warning. Lower movement rates or shorter durations don’t reach the threshold, and a longer duration would also eventually trigger, but the standard, tested condition is high rate for roughly three seconds. When this warning sounds, it’s a cue to verify trim inputs and readiness to manually control or cut out trim as needed to prevent a runaway.