What is the maximum flap extension in icing conditions?

• A. 15 degrees
• B. 20 degrees
• C. 30 degrees
• D. 10 degrees

Answer: (A)

In icing conditions, surfaces accumulate ice that disrupts the smooth airflow over the wing. Extending the flaps increases surface area and camber, raising lift but also making ice buildup on the flap more likely and more disruptive. Keeping flap extension limited to a modest amount helps preserve predictable handling and stall characteristics while still providing enough lift for approach and landing. Extended flaps beyond this point can lead to degraded control and more abrupt changes in flight behavior if ice is present. For the PC-12 NGX, the safe maximum in icing conditions is 15 degrees.