Process for producing a polyurethane-based fibre composite component part comprising the following process steps: a) producing a polyurethane reaction mixture b) applying the reaction mixture atop at least one of two carrier films c) bestowing the reaction mixture on the at least one of the two carrier films with reinforcing fibres d) bringing together the two carrier films from c) so that the carrier films on both sides surround the reaction mixture comprising the reinforcing fibres and a sandwich is formed, e) rolling the sandwich via rolls and/or rollers, optionally subsequent rolling up to afford the so-called sheet moulding compound or optionally subsequent cutting of the sandwich into so-called SMC pieces and stacking of these SMC pieces f) optionally storing the rolled-up SMC or the SMC stack g) converting the product from step e) or f) and removing the two carrier films h) optionally stacking a plurality of products from step g) i) moulding and completely curing the product from step g) or h) in a mould to afford the fibre composite component part, wherein the employed polyurethane reaction mixture consists of the following components A) one or more aromatic isocyanate components, B1) 70% to 100% by weight of one or more polyol components selected from the group consisting of polyether polyols, polyester polyols and polycarbonate polyols having 70% to 100% secondary OH groups based on all of the OH groups in the molecule and having a number-average OH number of 15 to 500 mg KOH/g (according to DIN EN ISO 53240, Part 2, November 2007 version) and a number-average functionality of 1.9 to 2.5, B2) 0% to 30% by weight of one or more polyols selected from the group consisting of polyether polyols, polyester polyols and polycarbonate polyols having a number-average OH number of 15 to 500 mg KOH/g (according to DIN EN ISO 53240, Part 2, November 2007 version) and a number-average functionality of 1.9 to 2.5 excluding the polyol component B1), wherein B1) and B2) sum to 100% by weight and at least 70% of the entirety of the OH groups of components B1) and B2) are secondary OH groups, C) optionally one or more short-chain polyols having a number-average OH number of 550 to 2000 mg KOH/g (according to DIN EN ISO 53240, Part 2, November 2007 version) and a number-average functionality of 1.9 to 6, D) one or more internal release agents, E) one or more thermolatent catalysts catalytically active at temperatures of 50°C to 120°C, preferably of 60°C to 100°C, F) inorganic fillers, G) optionally auxiliary and/or additive substances, characterized in that at 23°C the PUR reaction mixture has a starting viscosity of 2500 to 14000 mPas (measured according to DIN EN ISO 53019, Viscometry - Measurement of viscosities and flow curves with rotational viscometers, Part 1: Fundamentals and measurement geometry, September 2008 version, shear rate d/dt = 1 1/s), the content of inorganic fillers is 20% to 70% by weight, based on the polyurethane reaction mixture, and the ratio of the number of NCO groups of component A) to the number of OH groups of components B1), B2) and C) is from 1.35:1 to 10:1. a) producing a polyurethane reaction mixture b) applying the reaction mixture atop at least one of two carrier films c) bestowing the reaction mixture on the at least one of the two carrier films with reinforcing fibres d) bringing together the two carrier films from c) so that the carrier films on both sides surround the reaction mixture comprising the reinforcing fibres and a sandwich is formed, e) rolling the sandwich via rolls and/or rollers, optionally subsequent rolling up to afford the so-called sheet moulding compound or optionally subsequent cutting of the sandwich into so-called SMC pieces and stacking of these SMC pieces f) optionally storing the rolled-up SMC or the SMC stack g) converting the product from step e) or f) and removing the two carrier films h) optionally stacking a plurality of products from step g) i) moulding and completely curing the product from step g) or h) in a mould to afford the fibre composite component part, A) one or more aromatic isocyanate components, B1) 70% to 100% by weight of one or more polyol components selected from the group consisting of polyether polyols, polyester polyols and polycarbonate polyols having 70% to 100% secondary OH groups based on all of the OH groups in the molecule and having a number-average OH number of 15 to 500 mg KOH/g (according to DIN EN ISO 53240, Part 2, November 2007 version) and a number-average functionality of 1.9 to 2.5, B2) 0% to 30% by weight of one or more polyols selected from the group consisting of polyether polyols, polyester polyols and polycarbonate polyols having a number-average OH number of 15 to 500 mg KOH/g (according to DIN EN ISO 53240, Part 2, November 2007 version) and a number-average functionality of 1.9 to 2.5 excluding the polyol component B1), C) optionally one or more short-chain polyols having a number-average OH number of 550 to 2000 mg KOH/g (according to DIN EN ISO 53240, Part 2, November 2007 version) and a number-average functionality of 1.9 to 6, D) one or more internal release agents, E) one or more thermolatent catalysts catalytically active at temperatures of 50°C to 120°C, preferably of 60°C to 100°C, F) inorganic fillers, G) optionally auxiliary and/or additive substances,