The National Transportation Safety Board (NTSB) has released more information about a close call at Ronald Reagan Washington National airport that happened in March – two months after a deadly midair collision in the same airspace.
The NTSB on 3 July issued a preliminary report into the 28 March incident, which, like the January collision, involved a commercial passenger jet and military aircraft.
The report suggests a misunderstanding or miscommunication between air traffic controllers at two facilities resulted in a Delta Air Lines Airbus A319 taking off when it should not have.
At the time, a squadron of four US Air Force Northrop T-38 Talon training jets were performing a flyover mission of Arlington National Cemetery.
The T-38’s route was to bring them northwest over the Potomac River and then over airport’s northern edge. The Delta jet came within roughly 0.5nm (1km) of the T-38s, according to the NTSB’s initial report.
The agency has not said what it thinks caused the loss-of-separation event but the preliminary report reveals air traffic control (ATC) communications preceding the close call.
At 14:41 local time, a supervisor at the Federal Aviation Administration’s Potomac Consolidated Terminal Radar Approach Control (TRACON) centre told the lead controller at Reagan National that the T-38s had a “time on target” – presumably the time they should overfly the cemetery – of 15:21.
Therefore, the TRACON supervisor told the tower to plan for a “stop time of seventeen” – seemingly meaning that the tower should pause departures at 15:17.
But then at 15:02, a TRACON controller gave the T-38 pilots a different time on target, of 15:15.
Ten minutes later, at 15:12, the TRACON supervisor contacted the tower again, saying, “Stop all departures hard time is now seventeen”. It is unclear why the supervisor referenced that time.
The tower controller replied, “Hard time seventeen we will stop all departures” – indicating the tower still expected to stop departures at 15:17, as initially told.
Meanwhile, Reagan National controllers continued clearing aircraft to depart. One of those was Delta flight 2983, which at 15:15 was cleared to take-off from runway 19.
As the Delta jet was rolling, the TRANCON supervisor reached the tower again, asking why aircraft were still taking-off and ordering all take-offs halted. The tower controller said they had expected to pause departures at 15:17 and that it was too late for the Delta jet to stop.
The A319 was closest to the T-38s when it was just south of the airport, flying over the Potomac River. At that time, the T-38s were east of the Delta jet, flying northwest.
The NTSB’s investigation is ongoing.
So too is the agency’s inquiry into the 29 January midair collision near the same spot. That night, a US Army Sikorsky UH-60 Black Hawk collided with a PSA Airlines MHIRJ CRJ700 regional jet that was moments from landing at Reagan National.
The incident killed all 67 people on both aircraft – 64 people on the CRJ700 and three on the Black Hawk. Preliminary information suggests the Black Hawk had been flying higher than its assigned altitude.
