An existing gearbox design is to be checked before the expected service life due to bearing failures. The Institute of Engineering Design and Product Development: Research Department for Machine Elements and Aircraft Gearboxes, headed by Prof. Michael Weigand, was commissioned with the review. This recalculation checks the calculation and design of the gearbox and also recalculates all results using the latest standards and the latest manufacturer catalogs. This review of the existing gearbox design is intended to ensure that no fundamental calculation errors have led to premature failure of the bearings.