REPAIRS. damaged window panels and wind-shield may be removed and replaced if damage is extensive However, Certain repairs as prescribed in the following paragraphs can be made successfully without removing damaged part from aircraft Three types of temporary repairs for cracked plastic are possible. No repairs of any kind are recommended on highly-stressed or compound curves repair would be likely to affect pilot's field of vision.
Curved areas are more difficult to repair than flat areas and any repaired area is both structurally and optically inferior to the original surface.