New details emerged on Saturday about the final minutes of the Gulfstream G-100, which vanished from radar early in the morning while flying from Bermuda to Boston.
According to transmissions provided by LiveATC.net and reported by the Boston Globe, an air traffic controller asked whether the pilot was "coming in blind" and whether he was declaring an emergency. The pilot's initial response was inaudible. The controller said the signal was weak, and later confirmed the pilot had declared an emergency.
Clarence Togeretz, director of flight operations at Latitude Air Ambulances, which owned the aircraft, told CBC News that two pilots and two medical staff, all Canadian, were on board. The crew had flown to Bermuda to collect a patient and a relative, who are not Canadian, he said.
A local fire dispatcher asked emergency crews just after 1:00 EDT to prepare to meet a plane with an "electrical issue", and later said the aircraft had lost radio.
FlightAware tracking data shows the aircraft dropped from around 7,300 metres (24,000ft) to 3,300 metres (11,000ft) before communications went dark.
The FAA told the BBC it lost contact with the plane and issued a search and rescue notice just after 1:00 local time. The Guardian reported the alert notice was issued at about 1:20am. The air and water search is being conducted off the coast of Nantucket.
The plane departed Bermuda's L.F. Wade International Airport at 23:40 local time and was due at Boston's Logan Airport at 1:30 EDT.