Bell 407, Huntsville, Texas, June 8, 2008–The Board determined the probable cause of the EMS 407 accident was the pilot’s failure to identify and arrest the helicopter’s descent. Contributing to the accident was the pilot’s inadvertent flight into IMC and the limited outside visual reference due to the dark night conditions, low clouds and fog. The helicopter, operated by PHI, had been called in after another EMS operator had “aborted” the same patient-transfer mission an hour-and-a-half earlier because of low clouds and visibility near the spot where the PHI helicopter eventually went down. The PHI pilot was not using night vision goggles, but the helicopter was equipped with the Aviation Night Vision Imaging System (cockpit lighting system that is compatible with night vision goggles).

The pilot, flight nurse, flight paramedic and passenger were killed.