Having spent the last 6 yrs. of my Army career instructing at Ft. Rucker, I have done thousands of touchdown autos. However since retiring and flying for commercial operators, I have only worked for one company that did them on annual recurrency. I'm here to tell you that doing touchdown autos is a perishable skill,ie use it or lose it. For the last several years I have been doing autos with a power recovery. And then only once a year. Not nearly enough practice to remain skillful. If you work for an operator where you can do touchdown autos, you are luckier than most of us. Fly Safe!