Abstract: An onboard computer for an airplane, including: a processor able to carry out operational functions according to a configuration of the onboard computer; a means for storing the configuration of the onboard computer; a means for parameterizing the onboard computer from parameterization information; a mode S transmission chain as defined by the ICAO for transmitting operational data from the onboard computer to or from a ground station or another airplane, the operational data being processed by the operational functions carried out by the computer. The transmission chain is able to carry out, in mode S, the transmission of parameterization information, to or from the parameterization means.