If both the pitot tube and outside static vents are clogged, which instruments would be affected?

When both the pitot tube and outside static vents are clogged, the instruments that rely on these inputs will be affected significantly. The airspeed indicator uses the pitot tube to measure dynamic pressure (the difference between ambient air pressure and the pressure from airspeed), so if the pitot tube is clogged, the airspeed indicator will not function properly.

Additionally, the outside static vents provide static pressure information for the altimeter and the vertical speed indicator. If the static vents are clogged, the altimeter will not be able to accurately measure altitude changes, and the vertical speed indicator will also become inoperative as it relies on changes in static pressure to show the rate of climb or descent.

As a result, in this situation, both the altimeter and the vertical speed indicator, along with the airspeed indicator, would fail to provide accurate readings due to the lack of necessary pressure information from both the pitot tube and the static vents. Therefore, all three instruments would be affected.