Incident Overview
Prior to departure, a corrected flight plan was entered into the ATC computer for Air Force 1 (AF1) to follow a nonstandard route to Newark. After takeoff, AF1 was vectored northwest and handed off to New York Air Route Traffic Control Center (ZNY). The aircraft then proceeded east via Yardley (ARD) towards Newark.
Sequence of Events
Approximately 15 miles west of ARD, ZNY initiated a handoff to New York Terminal Radar Approach Control (N90). The N90 supervisor advised ZNY that AF1 should be descending to 9,000 feet during the handoff. An N90 controller then instructed a Washington Air Route Traffic Control Center (ZDC) controller in an adjacent sector to 'stop the Newark arrivals only.' The ZNY controller cleared AF1 to descend and change to N90 frequency but did not provide the mandatory pointout of AF1 to ZDC.
Meanwhile, Bar Harbor Flight 494 was being controlled by ZDC and was inbound to ARD on a northeast heading at 11,000 feet. Noting that an automated handoff had been accepted by N90, the ZDC controller cleared Flight 494 to descend to 7,000 feet and change to N90 frequency. The N90 controller recognized the developing situation but believed that all flights from the ZDC sector would be held in ZDC airspace. He subsequently took corrective action, but standard separation between the two aircraft was lost near the base of a 10,000-foot cloud layer.
Investigation Findings
The investigation revealed inadequate monitoring and coordination between ATC facilities. Several controllers and supervisors lacked training or awareness of their responsibilities.