September 14, 2001

Dear Ms. Knapp:

     On June 14, 2001, the Department of Transportation (DOT) submitted a Federal Aviation Administration (FAA) draft final rule titled "Revisions to Digital Flight Data Recorder Regulations for Boeing 737 Airplanes and for Part 125 Operators" to the Office of Management and Budget (OMB) for review under Executive Order No. 12866. This final rule would require all Boeing 737 series airplanes' flight data recorder systems to record additional flight data.

     Over the past month, we have raised questions and several concerns about the relative cost-effectiveness of requiring additional flight data recorder parameters that have been set forth in the final rule in light of additional steps that will be proposed in a related Notice of Proposed Rulemaking (NPRM) on general flight recorder improvements. That NPRM is currently under development and is expected to be submitted to OMB for review in the near future. We have suggested that some of these concerns might be addressed by discussing the NPRM with Departmental staff before taking action on the final rule.

     Since the resolution of the concerns will take some additional time, I am returning the draft final rule on flight data recorders to the Department for your reconsideration. Our staff is available for further discussion with you on the concerns that have been raised. We look forward to working with you to improve this important rulemaking effort.