If you fly single pilot, you don't have that backup. But you can gear your thinking to be the next best thing. As part of their procedures, many single pilots use some of the same callouts that would normally be sung out by a copilot. For example, as the airplane approaches a target altitude, the copilot will call out "1,000 to go," "500 to go," etc. On approach, the copilot will call out the same altitude warnings for minimums. Single-pilot operators are often urged to make their own callouts to themselves.