On August 14, 2019, about 1800 Pacific daylight time, an experimental AutoGyro Cavalon gyroplane, N477AG, was substantially damaged when it was involved in an accident near Shelton, Washington. The pilot received minor injuries. The gyroplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. According to the pilot, he was conducting stop-and-go takeoffs and landings from runway 23. He reported that he had done three or four takeoffs and landings before the accident and the gyroplane had been lifting off the runway at about 52 miles per hour (mph). On the accident takeoff attempt, the pilot reported that, before the takeoff roll, the rotor indicated 190 rpm, which was 10 rpm less than recommended by the manufacturer. During the takeoff roll, he observed the speed of the gyroplane was almost 60 mph. He said that he pulled the control stick back and the gyrocopter pitched up and yawed to the right and came immediately down. He heard a loud bang, and the gyroplane impacted the runway. Examination of the accident site revealed that the gyroplane impacted the runway slightly left of centerline, rolled onto its left side, and slid about 170 ft to the left edge of the runway. Numerous rotor blade and propeller contact marks were present along the path, consistent with rotation of both components. All major components remained attached to the gyroplane. Examination of the empennage revealed damage to the top side of the left vertical stabilizer consistent with rotor impact. A visual inspection of the fuselage and engine revealed no pre-impact mechanical failures or malfunctions that would have precluded normal operation. A review of the pilot’s logbook revealed that he had accrued about 73 total hours of flight experience in the accident gyroplane. The last flight documented in the logbook was dated August 14, 2019, the day of the accident. The previous flight occurred on August 10, 2019. The FAA Rotorcraft Flying Handbook, FAA-H-8083-21, states in part: Using coordinated throttle and flight control inputs, balance the gyroplane on the main gear without the nose wheel or tail wheel in contact with the surface. At this point, smoothly increase power to full thrust and hold the nose at takeoff attitude with cyclic pressure. The gyroplane will lift off at or near the minimum power required speed for the aircraft. And On a gyroplane with a semi-rigid, teeter-head rotor system, blade flap may develop if too much airflow passes through the rotor system while it is operating at low r.p.m. This is most often the result of taxiing too fast for a given rotor speed. The Cavalon Owner’s Manual, Section 4.8, Take-off Procedures, states in part: Carefully increase throttle (~ 20 R-RPM/sec) to 200 R-RPM – max. 220 R-RPM. This section also contains a warning that states in part: Take Care! Slow rotors can stall and flap, causing expensive aircraft damage. If in doubt, abort the take-off run and restart. The Cavalon Owner’s Manual, Section 4.9, Takeoff Run, states in part: Maintain attitude until speed increases and gyroplane lifts off (at about 50 mph, depending on loading and rotor).