Abstract: A new operating system is provided with two layers having different access authorizations. For security reasons a memory for basic system routines can be accessed only from a kernel layer, but not from an application layer. By providing a respective program that is executable in the respective layer, it is possible, while complying with the security stipulations, for the memory to be accessed and, consequently, for a new version of the basic system routines to be made available to the data processing system.

Abstract: This invention relates to a process for preventing undesired contact with land or water by low-flying aircraft which are assigned a minimum altitude and which are provided with instruments for measuring altitude, airspeed, angle of path, and transverse acceleration,Comprising measuring the rate of descent (H),transverse acceleration (b.sub.Q), when gravitational acceleration is eliminated,And altitude (H) to thereby ascertain whether the aircraft is above a given limiting altitude (H.sub.limit) determined from its ability for transverse acceleration and its flight data,And correcting the aircraft by the maximum feasible transverse acceleration (b.sub.Q max) when for a given measured value of altitude (H), the altitude is below the limiting altitude (H.sub.limit).