Where is a typical location for a pitot drain to ensure proper drainage?

• A. On the top surface of the fuselage.
• B. In the pitot line near the tube or in the instrument housing.
• C. Behind the cockpit window.
• D. In the static port.

Answer: (B)

Moisture that can collect in the pitot line must be able to escape before it affects the dynamic pressure that feeds the airspeed indicator. Placing the drain in the pitot line near the tube or inside the instrument housing puts the drainage right where any condensate or water can vent away from the pressure line and the instrument, helping prevent water or ice from blocking the line and causing erroneous readings. Draining on the top surface of the fuselage or behind the cockpit window wouldn’t reliably remove moisture from the pitot system and could introduce contamination or icing effects. A drain located in the static port would contaminate the static pressure system and distort altitude/vertical speed indications, which is undesirable.