What are the three axes of an airplane?

• A. Longitudinal, lateral, and vertical
• B. Pitch, roll, and yaw
• C. Altitude, heading, and bank
• D. X, Y, and Z

Answer: (A)

The three axes are defined by directions through the aircraft: the nose-to-tail direction is the longitudinal axis, the wingtip-to-wingtip direction is the lateral axis, and the top-to-bottom direction is the vertical axis. Rotations occur around these axes as roll about the longitudinal axis, pitch about the lateral axis, and yaw about the vertical axis. This is why the first option is the best answer—the axes themselves are named for their physical directions, and the associated movements are the rotations around them. The other choices mix up actions with axes or use different reference concepts (like altitude, heading, and bank or generic X, Y, Z) that aren’t the conventional aviation axes.