The flight instructor in the retractable-landing gear airplane reported that, during final with student at the controls, there were no abnormal weather conditions, but as the airplane passed over the runway threshold, the airplane encountered "severe wind shear" that he believed to be a "microburst." The airplane then pitched up, rolled left, and the instructor and student added full power to go around. During the attempted go-around, the instructor took control of the airplane with the landing gear down, full flaps, and the propeller full forward. He added that the airplane "simply" did not have enough performance to climb. Subsequently, the airplane drifted left of the runway and impacted a gravel hill. The airplane sustained substantial damage to the fuselage and right wing. The flight instructor reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation. An automated weather observation system about 14 nautical miles from the airport reported that, about the time of the accident, the wind was variable at 3 knots, temperature 73°F, dew point 68°F, altimeter 30.14 inches of mercury, and few clouds at 500 ft. The airplane landed on runway 3. The pilot reported that the weather at the airport was wind light and variable, visibility 10 miles, and few clouds at 2,000 ft. The instructor reported the wind as calm to light and variable, visibility 10 miles, and few clouds at 5,000 ft. The instructor further reported that, during the go-around, the airplane's configuration with full flaps for landing was not changed. The airplane's Pilot's Operating Handbook, "Go Around (balked landing)," stated that, following establishing a climb, the flaps should be reduced to the takeoff setting.