Landing gear steer-by-wire control system; digital vs. analog study

A worthiness study in which the digital steer-by-wire control system was compared to an analog one using the life-cycle cost procedure is presented. The purpose of the study was to determine whether the higher reliability, ease of test, decrease in maintenance cost, and lower delay and cancellation rates foreseen for the digital system were worth increased recurring and nonrecurring costs. A potential drawback is the cost of the software development and certification. It is strongly influenced by proper programming techniques and good definition of requirements. The life-cycle cost analysis has shown that it is advantageous to make a large initial investment in technology that will be paid back over the life of the system