The Flight Deck Access Panel alarm pattern is on for 4 seconds and silent for 9 seconds. Which option represents this cycle?

The Flight Deck Access Panel alarm pattern is on for 4 seconds and silent for 9 seconds. Which option represents this cycle?

• A. 2 seconds on / 5 seconds off
• B. 6 seconds on / 8 seconds off
• C. 4 seconds on / 9 seconds off
• D. 5 seconds on / 10 seconds off

Answer: (C)

Pattern recognition: the alarm pattern is a repeating cycle of the indicator being active (on) for a set number of seconds, then silent (off) for a set number of seconds. Here, the alarm is on for 4 seconds and then off for 9 seconds before repeating. That makes the cycle 13 seconds long, with a 4-second on-phase followed by a 9-second off-phase. The option that exactly matches these durations represents the same repeating pattern. Other options use different on/off durations, so they don’t reproduce the same cycle.

Pattern recognition: the alarm pattern is a repeating cycle of the indicator being active (on) for a set number of seconds, then silent (off) for a set number of seconds. Here, the alarm is on for 4 seconds and then off for 9 seconds before repeating. That makes the cycle 13 seconds long, with a 4-second on-phase followed by a 9-second off-phase. The option that exactly matches these durations represents the same repeating pattern. Other options use different on/off durations, so they don’t reproduce the same cycle.