Graphic displays in small aircraft: A proof of concept using a low-cost air-data computer

In order to provide a higher degree of safety and a decrease of the workload of the pilot in modern aircraft an air data computer is used to calculate the necessary flight parameters from the sensor inputs. These parameters are then displayed on a graphics display (EFIS, Electronic Flight Instrument System) in an integrated and clear manner. Unfortunately these air data computers and graphic displays are not used in small aircraft due to the high costs involved. Nowadays new fast signal processing chips and graphic displays are available which are relative low-cost and, therefore, are possible candidates for performing the task of the air data computer and graphic display in small aircraft. Demonstrated is in this report that an ordinary personal computer, used as air data computer, is capable of calculating the necessary parameters and driving a graphics display. As an air data computer is used a 80386/387 as host and a TIGA-card (Texas Instruments Graphics Architecture) as display driver for a 1024x768 16 colour display. A primary flight display (PFD) and a navigation display (ND) are developed together with the necessary software to calculate the parameters for the displays. The program run-times were measured and turned out to be sufficiently low so an acceptable update-rate could be obtained. The update-rate for the PFD is: 869 Hz & the update-rate for the ND is: 22 Hz. Excluded from these update-rates is the time consumed by the processor for building the display. In a real aircraft this would be done by a separate processor in order to obtain a program independent update-rate.Applied Science