The pilots of the UPS Boeing 747-400 cargo airplane that crashed on September 3 reported smoke in the cockpit as they tried to return to Dubai International Airport, according to a preliminary report issued by the UAE General Civil Aviation Authority (GCAA) on Sunday.

The airplane had departed Dubai International Airport at 6:53 p.m. local time for Cologne, Germany. At 7:15 p.m., UAE ATC Center received information from Bahrain that the crew could not maintain altitude and had turned around to attempt an emergency landing in Dubai.  

ATC issued clearance as the aircraft approached some 22 nm from the airport. It passed over the airfield “very high,” according to the report, and made a right turn. The aircraft then tracked southwest and rapidly lost altitude. At approximately 7:42 p.m. local time, ATC lost radar contact. The 747 crashed in an unpopulated area between Emirates Road and Al Ain Highway 50 minutes after departure. Both pilots died in the crash.   

The GCAA immediately dispatched an investigation team, which recovered the cockpit voice recorder some six hours after the accident. Investigators retrieved the flight data recorder earlier today.

A team from the NTSB arrived in the UAE on September 5 to assist with the investigation.

NTSB Chairman Deborah Hersman has designated senior air safety investigator Bill English as the U.S. accredited representative. His team includes NTSB specialists in the areas of human performance, fire, operations and systems. The team also includes technical advisors from the FAA, Boeing, UPS, GE and Independent Pilots Association.