Definition
An empennage configuration in which the horizontal stabilizer is mounted directly to the aft fuselage at the base of the vertical stabilizer, placing the elevator within the propeller slipstream and the wing's downwash during normal flight.
Plain English
The standard tail layout where the horizontal tail surfaces sit low on the back of the airplane, attached to the fuselage rather than up on top of the fin.
Context Anchor
Seen when comparing airplane tail designs, especially conventional-tail airplanes with T-tail airplanes.
Derivation
Conventional' comes from the Latin 'conventio' meaning an agreement or common practice. It is called conventional because this layout has been the most common tail arrangement since the early days of aviation.
Why Pilots Care
Because the elevator sits in the propeller slipstream, it remains effective at low airspeeds, which helps with elevator authority during takeoff rotation and slow flight. This handling characteristic differs noticeably from a T-tail aircraft.
Intuition Check
Conventional does not mean safer, simpler, or required by regulation. Here it means the standard low-mounted tail arrangement used for comparison with a T-tail.
Example Sentence 1
The Cessna 172 has a conventional-tail, so the elevator stays in the propeller slipstream and remains responsive at low airspeeds.
Example Sentence 2
Pilots transitioning from a T-tail to a conventional-tail aircraft notice the different pitch response during takeoff rotation.