The General Aviation XFA was an American prototype biplane fighter aircraft.
Delivered for evaluations in 1932, it showed poor flying characteristics, including longitudinal instability and over-sensitive controls.
General Aircraft increased the area of the tail surfaces and made other changes, then returned the prototype for more testing, after testing, the stability problems were worsened.
The plane would nose up with more throttle, but then drop its nose when the throttle was reduced.
After another round of modifications, and some close calls, the plane was finally classed as unsafe, and testing was abandoned.