Definition
A flight maneuver in which the nose of the aircraft is held approximately level while the tail is swung from side to side using rudder, producing a side-to-side yawing motion. It is used primarily as a means of slowing the aircraft or losing excess airspeed on approach, particularly in aircraft that lack flaps.
Plain English
A maneuver where the pilot uses the rudder to swing the tail left and right, like a fish moving its tail through water. The extra side-to-side motion creates drag and helps slow the aircraft down.
Context Anchor
Most often encountered in taxiing discussions, especially with airplanes where the pilot’s forward view is partly blocked by the nose.
Derivation
Named for the way a fish moves its tail from side to side to push itself through water. The aircraft's tail moves in a similar back-and-forth pattern, which is why the maneuver took the name.
Why Pilots Care
Unintentional fishtailing signals loss of directional control and can escalate into a ground loop if uncorrected.
Intuition Check
Fishtail does not always mean the airplane is skidding out of control. In aviation use, it can also describe an intentional side-to-side taxi motion used to see ahead.
Example Sentence 1
With no flaps installed, the pilot used a gentle fishtail on final to bleed off the extra airspeed before touchdown.
Example Sentence 2
A strong crosswind caused the taildragger to fishtail during the landing roll.