Which combination of atmospheric conditions will reduce aircraft takeoff and climb performance the most?

Choices

• Low temperature, low relative humidity, and low density altitude.

  These conditions IMPROVE performance — opposite of what the question asks.

• ✓ High temperature, high relative humidity, and high density altitude.correct

  High temperature, high humidity, and high density altitude all reduce engine power, propeller efficiency, and aerodynamic lift. Together they significantly degrade takeoff and climb performance. Density altitude is pressure altitude corrected for nonstandard temperature; humidity displaces oxygen and further reduces engine output.

• High temperature, low relative humidity, and low density altitude.

  Low density altitude actually improves performance.

• Low temperature, high relative humidity, and low density altitude.

  Low density altitude improves performance regardless of humidity.