Describe the tools used to check control surface travel?

• A. A universal propeller protractor or special control surface protractor.
• B. A ruler and tape measure.
• C. A borescope.
• D. An anemometer.

Answer: (A)

Measuring control surface travel requires quantifying the angular movement of the surface from neutral to its maximum deflection in both directions. A universal propeller protractor or a dedicated control surface protractor is best because it provides a direct, readable angle relative to the hinge line or a fixed reference on the aircraft. You set the instrument on the hinge line, read the neutral position, deflect the surface to the specified limits, and read the travel angles. This method gives you the exact angular travel in degrees that the manufacturer specifies. A ruler and tape measure only measure linear distance, not angle, so they can’t reliably verify angular travel. A borescope is for internal inspection, and an anemometer measures airspeed, which isn’t related to how far the surface can move.