1. A channel for an automatic flight control system comprising: a set of input devices, a set of output devices, a first digital processor, a second digital processor, a data control system intercoupling said set of input devices, said set of output devices, said first digital processor and said second digital processor for transferring data signals, address signals and control signals therebetween, said first digital processor having access of said data control system for a first predetermined time interval and said second digital processor having access to said data control system for a second predetermined time interval, first limiter means associated with said first digital processor for disabling access of said first digital processor to said data control system whenever said first digital processor maintains access thereto for a time interval greater than said first predetermined time interval, second limiter means associated with said second digital processor for disabling access of said second digital processor to said data control system whenever said second digital process maintains access thereto for a time interval greater than said second predetermined time interval.