Flight voice recordings from a Japan Coast Guard plane involved in a fatal collision were released Wednesday, reinforcing the view that its crew likely erroneously believed the aircraft was allowed to enter the runway when it was hit by a Japan Airlines jetliner at Tokyo's Haneda airport on January 2.
The co-pilot correctly repeated the airport traffic controller's instruction to taxi to a holding point where it would await clearance to enter the runway. But subsequent exchanges among the crew suggest they believed they had been given permission to enter, according to a Japan Transport Safety Board report.
According to the report, a traffic controller told the coast guard plane that it was "No. 1" in the order of takeoff and instructed it to "taxi to holding point C5." The co-pilot responded, "Taxi to holding point C5," and it was "No. 1."
The plane's captain also repeated "No. 1" and "C5" and instructed the co-pilot to proceed with preparations for departure. The aircraft then entered the runway.
Based on the content of voice recorders retrieved from the accident, the only talk on board the plane was about their mission to help the people affected by the magnitude-7.6 earthquake that struck the Noto Peninsula and surrounding areas on the Sea of Japan coast the previous day, it said.
The collision killed five of the six people aboard the coast guard's Bombardier DHC8-300, while all 379 people aboard the JAL Airbus A350 escaped despite flames engulfing the plane.
The report said the controller was focused on monitoring the JAL plane that was set to land on the runway and as such was unaware of the erroneous entry into the runway by the coast guard plane.
A runway entry alert was displayed on a desktop screen but the controller apparently did not notice it, the report said.
The crew of the JAL jetliner, for its part, could not visually confirm the presence of the coast guard plane on the runway before touchdown. According to the report, not only were the lights of the plane and the runway both white but the accident occurred after sunset with little to no moonlight.
The escape of all JAL passengers and crew, which took 18 minutes, was widely praised, with the report crediting crew members for their appropriate instructions.