When changing the altimeter setting to a LOWER value, how does the indicated altitude change?

When the altimeter setting is changed to a lower value, the indicated altitude will decrease. This is because the altimeter measures altitude based on air pressure. When the atmospheric pressure decreases, as it does with a lower altimeter setting, the altimeter will interpret this change as a reduction in altitude.

For example, if you are flying at a certain altitude and the pressure setting on your altimeter is adjusted downwards, the instrument will show a lower altitude than before the adjustment. This reflects the fact that, with the change in pressure, the aircraft is now "closer" to the point where the pressure reading matches the new setting, which results in a lower indicated altitude.

Understanding this relationship between altitude and pressure settings is crucial for ensuring accurate altitude readings and maintaining proper flight operations.