On Thursday, March 6th, the National Transportation Safety Board (NTSB) released its preliminary report about the Learjet 55 aircraft that crashed in Philadelphia, Pennsylvania. On Friday, January 31st,

The cockpit voice recorder (CVR) found in the fatal Jan. 31 medical jet crash in Northeast Philadelphia was not recording and likely hadn't recorded audio for several years, according to a preliminary report from the National Transportation Safety Board.

Jeff Guzzetti, a former NTSB investigator, said that the lack of a functional voice recorder would make investigating the nature and cause of the crash much more difficult — and was a violation of FAA rules for foreign air carriers.