How is the CHR feature of the Clock reset?

How is the CHR feature of the Clock reset?

• A. By pushing the RST button
• B. Turning the knob clockwise
• C. Using the MCDU reset command
• D. Pressing the CLR button

Answer: (A)

The CHR function is the chronometer inside the Clock, used to measure elapsed time. Resetting it is done with the dedicated RST pushbutton—pressing it zeros the elapsed time and prepares the chronometer for a new timing interval. The other actions don’t reset CHR: turning the knob clockwise changes the clock setting or value, not the elapsed time; the MCDU reset command affects the MCDU, not the Clock’s CHR; and the CLR button clears a current input or field rather than the CHR count. So the only way to reset the CHR function is to press the RST button.

The CHR function is the chronometer inside the Clock, used to measure elapsed time. Resetting it is done with the dedicated RST pushbutton—pressing it zeros the elapsed time and prepares the chronometer for a new timing interval. The other actions don’t reset CHR: turning the knob clockwise changes the clock setting or value, not the elapsed time; the MCDU reset command affects the MCDU, not the Clock’s CHR; and the CLR button clears a current input or field rather than the CHR count. So the only way to reset the CHR function is to press the RST button.