The UK’s Air Accidents Investigation Branch is probing the causes of a Cessna Citation II crash that closed Birmingham (UK) Airport for several hours on Friday. The aircraft crashed while attempting to land at around 3:35 p.m. local time during foggy conditions. Several eyewitnesses reported seeing smoke coming from the aircraft as it approached the runway and, according to airport officials, it hit the antenna of the instrument landing system as it came in to land. The Citation was operated by Liverpool-based charter operator AD Aviation. There were no passengers on board, but the jet was carrying a human liver being transferred to Birmingham for a transplant. Police were able to retrieve the liver from the wreckage and get it to the local hospital in time for the surgery to be completed. The two pilots were taken to a hospital. According to local press reports, the captain was more seriously injured, which is consistent with photos showing more damage to the left side of the aircraft. The copilot suffered burns but was discharged from the hospital on Saturday. Birmingham Airport was closed for almost 24 hours after the accident.