Which of the following errors would result from a blocked static port?

When the static port becomes blocked, it can create significant errors in how various instruments interpret air pressure changes, especially during altitude changes. The altimeter, Vertical Speed Indicator (VSI), and airspeed indicator rely on static pressure for accurate readings.

In the case of airspeed, if the static port is blocked, the air pressure reading may not change as the helicopter changes altitude, which can give a false airspeed indication. For example, while descending, the airspeed indicator could show slower speeds than actual since it does not correctly account for increasing dynamic pressure as the helicopter descends. This discrepancy leads to airspeed under-reporting during a descent, making it the correct conclusion for this situation.

The other options suggest that all other instruments would function correctly, which is not accurate when a static port is blocked. The altimeter would likely freeze at its last reading because it can’t sense changes in altitude, and the VSI would indicate zero or invalid rates of climb or descent since it also relies on correct static pressure. Therefore, those instruments would not provide correct changes, further highlighting why the airspeed under-reporting is the significant error resulting from a blocked static port.