What is the minimum height of the letters of the registration marks displayed on the vertical stabilizer of an airplane?

• A. 4.0 inches
• B. 5.0 inches
• C. 5.9 inches
• D. 6.5 inches

Answer: (C)

The correct answer regarding the minimum height of the letters of the registration marks displayed on the vertical stabilizer of an airplane is 5.9 inches. According to the Canadian Aviation Regulations, specifically CAR 601.02, registration marks must be legible and displayed clearly on the aircraft. The regulation specifies that the height of the letters must not be less than 5.9 inches to ensure adequate visibility from a distance.

This minimum height is important for identification and regulatory compliance, allowing for quick recognition by air traffic control and other aircraft, thereby enhancing safety in aviation operations. Ensuring that registration marks meet the specified dimensions helps maintain standardization across the aviation sector, which is critical for both commercial and private aircraft operations.

In contrast, other options do not meet the regulatory requirement for minimum height and therefore would not be appropriate choices. The options mentioned provide lower heights, which would compromise the legibility and visibility of the registration marks, potentially leading to safety concerns and difficulties in identification.