Air traffic transmissions with the Colgan Air Bombardier Q400 which crashed on approach to Buffalo give no immediate indications of any problems before controllers suddenly lost contact with the flight.
The audio record also reveals that, as controllers searched for the missing aircraft, they queried whether a following flight was experiencing icing conditions.
Weather information at the time of the accident, about 22:20 yesterday, points to light snow, a temperature of 1°C, and gusting winds of up to 22kt.
Air traffic communications show that, at around 22:15, a Buffalo approach controller instructed Colgan Air flight 3407 to turn left, heading 260°.
The controller refers to the aircraft being 3nm from 'KLUMP', the identifier for the outer marker to runway 23 at Buffalo Niagara International Airport.
Approach control also tells the aircraft to maintain an altitude of 2,300ft until it is established on the localiser for a runway 23 instrument landing system approach.
About a minute later, the aircraft is told to contact Buffalo tower's frequency, 120.5MHz, and the approach controller hands off the flight, telling the crew: "Have a good night."
First indications of problems come about a minute after the hand-off, when Buffalo controllers try to contact the flight, calling it three times in the space of 30s, with no reply from the crew.
A controller contacts another inbound flight, Delta Air Lines' DL1998, asking: "Look off your right side, about five miles, for a Dash 8, it should be at 2300 [ft], do you see anything there?"
DL1998's crew replies "negative" and then adds that there is "nothing on the TCAS", referring to there being no indication of another aircraft on its traffic collision-avoidance system.
At about 22:20, after further failed attempts to reach the Q400, the controller can be heard organising search efforts in the region to see if "anything is on the ground", adding: "The aircraft was five miles out and all of a sudden we have no response from that aircraft."
He adds that the Q400 was "over the marker" but says: "We're not talking to him now."
Shortly afterwards there is another communication with DL1998, and the controller queries whether the Delta flight is picking up any icing. The crew indicates that it was experiencing icing from 6,500ft to 3,500ft but the flight is "not building any more".
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There are no indications of survivors from the 48 passengers and crew on board flight 3407. Continental Airlines states that it has dispatched representatives to Buffalo to assist with the inquiry.