An aircraft engine having an oil circuit and a transmission that can be supplied with oil via the oil circuit. Oil fed to the transmission can be directed out of the transmission into an oil reservoir, from which oil can be introduced directly back into the transmission via a hydraulic line path. According to the invention, the oil fed to the oil reservoir can only be fed to the hydraulic line path below a defined filling level of the oil reservoir. When the defined filling level of the oil reservoir is reached, oil can also be introduced into a further hydraulic line path.