What defines a T-tail configuration?

• A. A tail configuration with the horizontal stabilizer mounted low on the aft fuselage.
• B. A tail where the horizontal stabilizer is on the bottom of the vertical stabilizer.
• C. An aircraft with the horizontal stabilizer mounted on the top of the vertical stabilizer, forming a T.
• D. A vertical stabilizer with no horizontal stabilizer.

Answer: (C)

A T-tail is defined by the horizontal stabilizer being mounted on top of the vertical stabilizer, forming a T shape. This places the tailplane in cleaner, undisturbed air away from the wing and fuselage wake, which often gives more effective elevator control and reduces interference in certain flight regimes. While convenient in some designs, this arrangement can introduce a deep-stall risk if the tail enters the wing’s wake at high angles of attack, so designers address that with specific features or procedures. The other configurations describe stabilizers mounted lower on the aft fuselage, on the bottom of the vertical stabilizer, or having no horizontal stabilizer at all, none of which produce the characteristic top-mounted tailplane of a T-tail.