A process of repairing a sandwich structural member comprising a first, fibre-reinforced plastics facing layer, a second plastics facing layer and a core disposed between the first and second plastics facing layers (4, 6) and having pores, the method comprising the steps of: a) removing a portion of the first plastic cover layer to form a repair opening providing access to a repair area of the core, b) replacing at least a portion of the core from the repair region with a repair core, c) inserting fibres, in particular a prepreg material with the fibres, into the repair opening, d) placing a cover element, preferably a cover plate, on the first plastic cover layer so that the cover element extends completely over the repair opening and an annular sealing surface is formed around the repair opening between the cover element and the first plastic cover layer, wherein the cover element comprises a first channel extending from an upper side channel opening to a lower side channel opening arranged opposite to the repair opening, characterised by e) piercing a hollow needle through the cover member and fibres into the repair core such that a tip of the hollow needle extends into an end portion of the repair core remote from the repair opening, f) establishing fluid communication between a container of liquid resin and an end of the hollow needle remote from the tip, g) drawing fluid, in particular air, through the first channel from the 30 repair region so that liquid resin flows through the hollow needle into the end portion of the repair core and flows to the fibres in the repair opening, h) stopping the suction from step g) when the liquid resin has flowed to the fibres, i) withdrawing the hollow needle from the sandwich member and the cover member, and j) curing the liquid resin in the sandwich member so that the repair opening is closed by cured resin with integrated fibres, which then form a fibre-reinforced plastic closure for the first plastic cover layer. a) removing a portion of the first plastic cover layer to form a repair opening providing access to a repair area of the core, b) replacing at least a portion of the core from the repair region with a repair core, c) inserting fibres, in particular a prepreg material with the fibres, into the repair opening, d) placing a cover element, preferably a cover plate, on the first plastic cover layer so that the cover element extends completely over the repair opening and an annular sealing surface is formed around the repair opening between the cover element and the first plastic cover layer, wherein the cover element comprises a first channel extending from an upper side channel opening to a lower side channel opening arranged opposite to the repair opening, characterised by e) piercing a hollow needle through the cover member and fibres into the repair core such that a tip of the hollow needle extends into an end portion of the repair core remote from the repair opening, f) establishing fluid communication between a container of liquid resin and an end of the hollow needle remote from the tip, g) drawing fluid, in particular air, through the first channel from the 30 repair region so that liquid resin flows through the hollow needle into the end portion of the repair core and flows to the fibres in the repair opening, h) stopping the suction from step g) when the liquid resin has flowed to the fibres, i) withdrawing the hollow needle from the sandwich member and the cover member, and j) curing the liquid resin in the sandwich member so that the repair opening is closed by cured resin with integrated fibres, which then form a fibre-reinforced plastic closure for the first plastic cover layer.