Story ID: 
Proposal Aims To Improve DFDR Information
By: Gordon Gilbert
Caption: The FAA is proposing to amend the digital flight data recorder (DFDR) regulations of Parts 121 and 135 to prohibit filtering of original parameter sensor s
Word Count: 155
The FAA is proposing to amend the digital flight data recorder (DFDR) regulations of Parts 121 and 135 to prohibit filtering of original parameter sensor signals. This proposed rule is based on recommendations issued by the NTSB and is intended to improve the accuracy and quality of the data recorded. During several accident investigations, the Board found that some DFDRs were filtering signals before they were recorded. “As a result, the data being recorded did not accurately reflect the aircraft’s performance or the movements of the flight control systems,” the agency said. According to the FAA, during the design of DFDR systems, it appears that “convenience and a desire to reduce cost and complexity by eliminating multiple data paths have led to the DFDR recording filtered data rather than raw data.” The FAA projects that the de-filtering modification would cost about $16,025 per airplane, although not all manufacturers agree. Comments on the proposal are due by February 13.