If the static port becomes iced during descent, what will happen to the trapped static pressure and the airspeed indicator reading?

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Multiple Choice

If the static port becomes iced during descent, what will happen to the trapped static pressure and the airspeed indicator reading?

Explanation:
When the static port is iced, the static pressure in the airspeed indicator system becomes trapped at the value it had when icing occurred. During a descent, ambient static pressure increases, but the trapped pressure does not change. Since airspeed indication is based on the difference between stagnation pressure and static pressure (Pt minus Ps), having Ps that is too low relative to the outside pressure makes that difference larger. A larger Pt−Ps difference makes the IAS appear higher than the aircraft’s true airspeed. So the trapped static pressure is too low, and the airspeed indicator will read higher than actual.

When the static port is iced, the static pressure in the airspeed indicator system becomes trapped at the value it had when icing occurred. During a descent, ambient static pressure increases, but the trapped pressure does not change. Since airspeed indication is based on the difference between stagnation pressure and static pressure (Pt minus Ps), having Ps that is too low relative to the outside pressure makes that difference larger. A larger Pt−Ps difference makes the IAS appear higher than the aircraft’s true airspeed. So the trapped static pressure is too low, and the airspeed indicator will read higher than actual.

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