Certified Flight Instructor - Flight Instructor Airplane Practice Exam

What airspeed indicator marking identifies the maximum structural cruising speed of an aircraft?

1. Red radial line.

2. Upper limit of the green arc.

3. Upper limit of the yellow arc.

4. Lower limit of the white arc.

The correct answer is: Upper limit of the green arc.

The maximum structural cruising speed, often referred to as VNO, is indicated on the airspeed indicator by the upper limit of the green arc. This marking serves as a critical parameter for pilots, as it indicates the highest speed at which the aircraft can safely be flown in turbulent air. Operating above this speed could lead to structural stress and potential failure, especially in rough conditions. The green arc represents the normal operating range of speeds for the aircraft, and VNO is the threshold between normal flight and maneuvering speeds where caution is advised. Other markings on the airspeed indicator serve different purposes: the red radial line typically denotes VNE (never exceed speed), the upper limit of the yellow arc indicates the maximum operating maneuvering speed, and the lower limit of the white arc represents stall speed in a specified configuration. Each marking provides essential information for safe operation, but for identifying the maximum structural cruising speed, the upper limit of the green arc is the correct reference.