The pilots at the controls of the UPS Airbus A300-600 freighter that crashed earlier today in Alabama had not issued a distress call before the incident, says the US National Transportation Safety Board (NTSB).

The agency, which sent an investigating team to the crash site at Birmingham-Shuttlesworth International airport, says it is still working to recover the flight recorders on the crashed aircraft.

NTSB board member Robert Sumwalt tells reporters during an afternoon press briefing in Alabama that the tail section of the aircraft, which houses the flight data recorder and cockpit voice recorder, is "still smouldering" nearly 12 hours after the crash.

"The first responders are out there continuing to put water, fire retardant, on that section of fuselage," says Sumwalt.

Initial information obtained by the NTSB indicates the pilots did not issue a distress call prior to the crash, he adds.

UPS has confirmed that both pilots were killed in the crash.

Enroute from Louisville in Kentucky, the aircraft, registration number N155UP, impacted trees on its descent to runway 18 at Birmingham before crashing into the bottom of a hill and breaking apart, says Sumwalt.

Debris then travelled up the hill, with the forward cockpit section of the fuselage coming to rest about 183m from the initial impact point and the wing and tail section coming to a rest 69m to 73m past the cockpit, he says.

The over-wing portion of the aircraft was "extensively damaged" by fire, he adds.

Visibility at the time of the incident was 10 miles and there were scattered clouds at 10,000ft above the area, Sumwalt says.

The NTSB is checking to see if the aircraft was carrying hazardous materials and is also verifying the condition of the airport's navigation aids at the time of the crash.

The crash occurred at 06:11 Eastern Time (05:11 local time), according to UPS. The aircraft, powered by Pratt & Whitney PW400 engines, was delivered to UPS in 2003 and had accumulated about 11,000 flight hours and about 6,800 flights.

Source: Air Transport Intelligence news