Position and Warning Systems (1) An airspeed indicator measures the differential between pitot and static air pressures surrounding the aircraft at any moment of flight. (2) An airspeed indicator measures the differential between pitot and cabin air pressures at any moment of flight. Regarding the above statements, a. both No. 1 and No. 2 are true. b. only No. 2 is true. c. only No. 1 is true.