What happened
Following takeoff from Bar Harbor, a corrected flight plan was entered into the air traffic control computer for Air Force 1 (AF1) to follow a nonstandard route to Newark. After takeoff, AF1 was vectored northwest with a handoff to New York ARTCC (ZNY), then eastbound via Yardley (ARD) toward Newark.
Approximately 15 miles west of ARD, ZNY initiated a handoff to NY TRACON (N90). A TRACON supervisor instructed ZNY that AF1 should descend to 9,000 feet during the handoff. The N90 controller then instructed the Washington ARTCC (ZDC) controller in an adjacent sector to "stop the Newark arrivals only." While the ZNY controller cleared AF1 to descend and change to the N90 frequency, they failed to provide a mandatory point-out of AF1 to the ZDC controller.
Simultaneously, Bar Harbor Flight 494 was being controlled by ZDC and was inbound to ARD on a northeast heading at 11,000 feet. Noticing that an automated handoff had been accepted by N90, the ZDC controller cleared Flight 494 to descend to 7,000 feet and change to the N90 frequency. Although the N90 controller noted a developing situation, they believed all flights from the ZDC sector would be held within ZDC airspace. While corrective action was eventually taken, standard separation between the aircraft was lost near the base of a 10,000-foot cloud layer.
Findings
The investigation revealed inadequate monitoring and coordination between air traffic control facilities. It was determined that several controllers and supervisors lacked the necessary training or awareness regarding their specific responsibilities.