April 16 is the comment deadline for two FAA proposals. The agency wants to amend digital flight data recorder (DFDR) regulations of Parts 121 and 135 to prohibit “filtering” of signals. During several accident investigations, the NTSB 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. That date is also the deadline for comments on a proposal that would revise the system of ratings for repair stations and require Part 145-certified repair stations to establish a quality assurance program.