Modular automatic test equipment for commercial airlines

THE DC‐10 era is effecting subtle changes in the maintenance procedures. The basic objectives of maintaining safe equipment at a reasonable cost have not changed. The means of achieving the objectives are changing. Digital equipment, which has so much to offer in terms of reliability, capability, and cost, will require a new degree of sophistication on the part of maintenance people and equipment. Digital circuits operate on the basis of information transfer at a high cyclic rate. The control of this data transfer is the function of special purpose digital computers. Although the computer has cither serial or parallel arithmetic organisation, the output information is in a serial digital format at a reasonably high output rate. These system characteristics have resulted in maintenance people requiring a new type of electronics knowledge — the ability to work with digital logic diagrams, computer organisation and computer programs. The performance data cannot be readily evaluated by voltage measurements or analog traces on an XY recorder as has been accomplished in the past. At the same time that the equipment is becoming more difficult to understand and test, manual testing is becoming more lengthy and, in some respects, tedious because of the digital mechanisation of the functions. Airlines will not be able to afford to use their skilled maintenance technicians for routine tasks. They will be better utilised for troubleshooting problems. As a result, the relatively unsophisticated test benches of the past are becoming obsolete and are being replaced by either sophisticated manual test equipment or sophisticated automatic test equipment.