Both NBAA and the National Air Transportation Association have called on the FAA to initiate a full rewrite of the Part 135 flight, duty and rest rules instead of relying on a new interpretation of flight time. NBAA said the FAA’s proposal to require a flight-by-flight determination of remaining duty time is too significant for implementation simply by a notice of proposed interpretation. Under the new interpretation, operators would no longer be permitted to extend a crew duty day for unforeseen circumstances that occur before departure of the final flight segment, such as late-arriving passengers and cargo. The proposed interpretation would clarify whether the crew may take off on the last leg of the flight, knowing in advance that the delays would extend the flight beyond a 14-hour duty day. Although the comment period closed yesterday, NATA noted that the FAA typically accepts and reviews late-filed submissions.