The expression “Fly off the Handle” is used to indicate that someone has become irrationally angry due to a complete loss of self-control.
Example in use: ‘Try not to make Sam mad. He has a tendency to fly off the handle at the slightest provocation.’
“Fly off the Handle” is an American phrase that alludes to the way that an axe head can fly off its handle if it becomes loose. The expression was first seen in print in 1834, in Thomas C. Haliburton’s The Attaché; or, Sam Slick in England: “He flies right off the handle for nothing.”