If the static port becomes blocked, how will the altimeter respond?

When the static port becomes blocked, the altimeter will "freeze" at the altitude at which the blockage occurs. This happens because the altimeter relies on atmospheric pressure readings from the static port to determine altitude. If the static port is blocked, the altimeter cannot sense changes in outside air pressure.

As the aircraft climbs or descends, the pressure outside changes, but the altimeter will not adjust to reflect these changes since it is still relying on the stale data from the blocked static port. Consequently, the altimeter will display a constant reading, effectively freezing at the altitude where the blockage occurred. This response can pose serious risks during flight, as it could lead to altitude misjudgment and potentially hazardous situations.

In contrast to other options, the altimeter does not simply remain unchanged in all scenarios or show an incorrect reading in a varying manner; rather, it becomes static. It does not display zero altitude unless the aircraft is indeed at sea level upon the blockage, which generally isn’t the case in flight situations. It may also read incorrectly, but the key characteristic of a blocked static port is that it "freezes" as opposed to giving variable readings.