Abstract: A waterproof sheet for a cargo chamber of an aircraft comprising a base sheet adapted to lie on the floor of the cargo chamber and having notched portions at positions corresponding to the doors of the cargo chamber; door sill flaps provided to the base sheet around the notched portions and adapted to be folded up and down at the time of opening and closing of the cargo chamber door; door sill protectors provided to the base sheet at the notched portions for protecting the door sill flaps; side sheets provided at the longitudinal sides of the base sheet and having tape fasteners for securing the side sheets to the wall of the cargo chamber, and end sheets provided at both longitudinal ends of the base sheet and the side sheets, the end sheets having tape fasteners for tucking them when the base and side sheets are properly positioned in the cargo chamber.