Page:CAB Aircraft Accident Report, American Airlines Flight 320.pdf/22

 autopilot approach criteria and limitations to all air carriers should be established, taking into account the particular autopilot used, the aircraft involved, and the approach facilities utilized. Accordingly, the Board has recommended to the FAA that it initiate a study of air carrier policies, procedures, and techniques for employing an autopilot for instrument approaches and take whatever action appears appropriate.

Although, as indicated in previous sections of this report, the Board does not believe that altimeter malfunctioning was a major factor in this accident, it is convinced that the searching investigation of the altimeters as a result of this accident has disclosed the need for changes in the procedures used to approve such items of equipment and instrumentation.

Units such as the Kollsman drum altimeter, the Eclipse-Pioneer Flight Director System, and the PB-20 autopilot are approved for civil use by the Federal Aviation Agency under the Technical Standard Order System. In obtaining approval for his product under this system, a manufacturer certifies to the FAA that he has complied with all of the specifications and has conducted all of the tests contained in the appropriate TSO. This certification by the manufacturer constitutes FAA approval, and the manufacturer is free to market his product and a prospective purchaser, such as an airline, is then able to install the item in an aircraft without further substantiation of the product. Typically, FAA's TSO program does not require inservice suitability testing of items that are approved, nor does it incorporate specific quality control standards. Furthermore, evidence developed during the Board's investigation and public hearing on this accident indicated that FAA had no overall definitive program for monitoring routine service difficulties on TSO items.

Service testing of novel designs before fleetwise installation is authorized would be very instrumental in uncovering design deficiencies in a product. The incorporation of specific quality control standards in the TSO and/or direct surveillance of the manufacturer's quality control organization by FAA inspectors would insure only high-quality products getting into service. Closer monitoring by the FAA of minor difficulty reports on newer TSO items would detect trends before a serious failure or malfunctioning occurred. These Board views have been conveyed to the FAA.

The Board also believes that the carrier has definite obligations in this area. In view of the novel presentation of the drum altimeters, the Board finds it difficult to understand why American did not at least incorporate this instrument in the Electra cockpit trainer used by the flight crews during their Electra training. Although this would not have been as beneficial as a more extensive preservice test evaluation of this instrument, it would at least have provided the flight crews with some experience on this important safety instrument before they used it in actual scheduled service. Similarly, the new instantaneous vertical speed indicator would have been a desirable instrument to incorporate in the cockpit trainer. In addition, added emphasis should have been placed on the difference between these new instruments and the older types during the crew training program until such time as it was evident that the various crews were experiencing no unusual amount of difficulty in effecting transition to the newer types.