How should a plane captain properly wipe the canopy?

Using short fore and aft strokes is the proper technique for wiping the canopy. This method is effective as it helps to minimize the risk of any debris or dirt being spread across the surface of the canopy, which could potentially scratch or damage it. The fore and aft motion allows for focused cleaning while maintaining control over the area being cleaned, reducing the chance of leaving streaks or smudges.

In addition, short strokes can help in areas that may require more precision due to the canopy's contours or the presence of any obstructions, ensuring that all parts of the canopy receive attention without the risk of causing damage or reducing visibility. Furthermore, this technique allows the plane captain to better observe the canopy for any signs of wear or damage during the cleaning process.