How does icing influence lift and drag on an aircraft?

• A. Icing reduces lift and drag increases.
• B. Icing reduces weight.
• C. Icing reduces drag and increases lift.
• D. Icing increases weight and drag and reduces lift.

Answer: (D)

Ice on a wing changes the flight characteristics in three main ways. First, it adds mass to the airplane, so the overall weight increases. That extra weight demands more lift to stay level, and at a given speed the wing has to work harder, which can lower performance and raise stall risk.

Second, ice increases drag. The added ice surface roughness and extra surface area act like more friction and form a larger obstruction to the airflow, so parasite drag goes up. The irregular shape also disturbs the smooth airflow over the wing, further increasing drag.

Third, lift is reduced. The ice distorts the airfoil’s shape, changing its camber and chord distribution and making the airflow less efficient at producing lift. The roughness and disturbance of the boundary layer cause earlier flow separation, so for the same angle of attack the wing generates less lift.

Because weight and drag rise while lift falls, icing moves the performance envelope in a way that aligns with the statement: icing increases weight and drag and reduces lift.