Page:NTSB Southern Airways Flight 932 report.pdf/41

 3.

Although the Safety Board has been unable to determine the probable reason for the unrecognized descent below MDA in this instance, the Board wishes to reiterate its concern with the general problem of landing and approach accidents and to reemphasize its interest in the various preventive measures which might prove useful in reducing the rate of these kinds of accidents, There is a need for all segments of the aviation industry to continue to focus attention on the unique demands for crew coordination and vigilance during nonprecision approaches. Area navigation systems, now in the final proving stages of development, will apparently provide descent guidance capability within the aircraft and should be standard equipment on all future transport category aircraft. The retrofitting of aircraft in the inventory should be expedited as much as possible.

The Safety Board also notes and supports the FAA in its issuance of Air Carrier Operations Bulletin No. 71-9 which emphasizes the common faults noted in nonprecision approaches and proposes several recommendations to eliminate these faults. (See Appendix F.)

In view of the foregoing, the Safety Board recommends that:


 * 1) All segments of the aviation industry continue to focus attention on the unique demands for crew coordination and vigilance during nonprecision approaches. Particular emphasis should be placed on the accelerated development of area navigation systems with vertical guidance capability and on heads-up display systems.

The Board, on February 13, 1968, supported a Notice of Proposed Rule Making which would require the installation of an altitude warning device for turbojet powered civil airplanes. The basis for this support, cited in the letter, was a series of aircraft accidents involving air carrier aircraft that had been involved in controlled crashes into the ground or water. Of the five accidents cited, three occurred during the final approach to landing. In the other two cases, the aircraft were descending in preparation for an approach and landing.

On January 17, 1969, writing with reference to accidents which occur during the approach and landing phase of flight, the Board recommended, among other things, the development and installation of audible and visual altitude warning devices and the implementation of procedures for the use of such devices. The FAA response to this recommendation was to cite its rule making dated September 1968, which required the installation of altitude alerting devices in all turbo powered civil aircraft. This device would provide both aural and visual indications to warn pilots when they approach selected altitudes during climbs,