The NTSB on Friday released a cockpit voice recorder transcript, group factual reports and other documents from the agency’s investigation of the Sept. 19, 2008, overrun crash of a Learjet 60 in Columbia, S.C. In that accident, the Learjet’s pilots attempted to abort the takeoff after a high-speed tire burst, according to the Safety Board. The twinjet hit an embankment and a post-crash fire ensued, killing two crewmembers and two passengers; two remaining passengers survived but suffered severe burns. The released group factual report focuses on the engine and thrust reverser systems in the accident airplane, records from other Learjets, the design of the engine and thrust reversers, changes made and certification. On July 21, the NTSB issued recommendations seeking changes to the Learjet 60’s thrust-reverser system. Meanwhile, the CVR transcript shows that the pilots realized something was wrong with the aircraft just seconds before the crash. The transcript indicates that the crew heard several sounds, described as “metallic clicks,” some 20 seconds before the recording ended upon impact. Further, the NTSB said there was a “high-frequency sound consistent with brake pedal application” five seconds after the crew heard the first of the two clicking sounds. Five seconds before the crash, the copilot told the tower controller, “Roll the equipment, we’re goin’ off the end.”