One of the two Phoenix television news helicopters was moving while the other remained relatively stationary just before the mid-air collision on July 27 that killed all four people aboard the rotorcraft. The two helicopters were among five that were covering a police chase on live television. Two pilots and two photographers aboard the KTVK (Channel 3) and KNXV (Channel 15) rotorcraft were killed. According to the preliminary accident report released by the National Transportation Safety Board, A pilot of one of the other news choppers told Safety Board investigators that the two accident helicopters were “positioned a reasonable distance apart.” As the action on the ground heated up, the two helicopters moved closer. Shortly thereafter, they impacted. Witnesses on the ground said the Channel 3 helicopter was hovering while the Channel 15 aircraft was maneuvering when the collision occurred. The federal air safety investigators said there was no visible sign of trouble before they collided. The report showed that neither helicopter moved erratically and no one reported hearing unusual aircraft noises or seeing smoke. Both rotorcraft (N13TV for KTVK and N15TV for KNXV) were American Eurocopter AS 350 B2s.