On May 9, 1991, the FAA stated that it was reviewing these safety recommendations. On August 1, 1991, the Safety Board stated that it was disappointed that the FAA failed to include any timetable for the completion of the review because untimely or missing DFDR documentation was adversely affecting ongoing investigations. The Board reemphasized its commitment to these recommendations, stating that it would continue to work with the FAA and the aviation industry to implement the recommendations.
On December 18, 1991, the FAA stated that it was planning to develop an AC to address the installation and maintenance of DFDRs and flight data acquisition units (FDAU). The FAA indicated that the AC would reference the appropriate regulatory requirements and contain the universal documentation format for each DFDR aircraft configuration and installation. The FAA further indicated that the baseline documents for the AC would be the universal format being developed by Aeronautical Radio, Inc., and the Board's proposed FDR configuration documentation standard.
On January 28, 1992, the Safety Board stated that it remained encouraged by the FAA's support for these safety recommendations. The Board believed that the FAA's plan to develop an AC that addresses the installation and maintenance of DFDR systems and references a universal documentation standard was a step in the right direction. However, the Board believed that the AC needed to be supplemented with permanent policy and guidance material so that FAA inspectors would require that the AC be implemented.
On April 22, 1994, the Safety Board stated that, in early 1993, FAA staff had indicated that the proposed AC had not been developed because the FAA was waiting for Aeronautical Radio, Inc., to publish the proposed documentation standard. Because Aeronautical Radio was unable to commit the resources needed to publish the proposed standard, the FAA proposed that the Board draft an AC that incorporated the draft Aeronautical Radio documentation standard. Safety Board and FAA staffs subsequently discussed and agreed on the principal elements of a draft AC based on the draft Aeronautical Radio documentation standards. On October 18, 1993, the Board provided a draft of the AC and DFDR documentation standards. However, the FAA made no progress toward implementing Safety Recommendations A-91-23 and -24, even with the Board's draft AC. The Safety Board continued to believe that the actions requested in these recommendations were essential and therefore urged the FAA to take the necessary actions.
On March 3, 1997, the FAA stated that it included information regarding the installation and maintenance of DFDRs and FDAUs in Notice N8110.65, "Policy and Guidance for the Certification and Continued Airworthiness of Digital Flight Data Recorder Systems." According to the FAA, the notice referenced the appropriate regulatory requirements and contained the universal documentation format for each DFDR aircraft configuration and installation. The FAA stated that the universal format developed by Aeronautical Radio, Inc., and the Board's proposed FDR configuration documentation standard were used as baseline documents for the notice.
On July 10, 1998, the Safety Board noted its disappointment that the AC had still not been completed. The Board stated that inclusion of guidance relating to FDR
