The tail section of an aircraft, including the vertical and horizontal stabilizers and control surfaces.
From French empennage, from em- + penne (feather, wing), literally 'feathering.' Named after a bird's tail feathers because they serve the same stabilizing function.
When the Wright Brothers designed their airplane, they were essentially giving it feathers—the empennage works just like a bird's tail, which is why engineers borrowed the French word for 'feathering' to describe it.
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