DUBAI // The pilots of the UPS cargo plane that crashed in Dubai last year may have been unable to steer because a fire in the cargo area caused the control cables to slacken, an interim report says.
Smoke that filled the cockpit could also have prevented the two US pilots, both of whom died in the September 3 accident, from seeing the instruments.
An interim investigation report released by the General Civil Aviation Authority (GCAA) last month also noted problems with the oxygen flow to the pilots’ masks may have been related to rising temperatures from the fire.
The GCAA report, the first since a preliminary report was released in April, offered new details about what went wrong aboard the Boeing 747, which crashed in the Nad Al Sheba military camp less than an hour after taking off from Dubai International Airport.
The pilots reported a fire 22 minutes into the flight and turned back towards Dubai, but overflew the airport. It crashed on the way to an emergency landing at Sharjah International Airport.
“The investigation has centred on a probably uncontained fire on the main cargo deck as the primary significant factor,” the interim report reads.
“The investigation is focusing on several possible ignition sources, primarily the location in the cargo of lithium and lithium-derivative batteries that were on board.”
The interim report used data from flight recorders, air-traffic control transcripts and a cockpit voice recorder. About 25 minutes into the flight, Capt Doug Lampe could be heard on the cockpit recorder saying he was not able to manually control the plane. The control cables ran above the probable location of the fire, the report said.
Although Capt Lampe’s controls were limited, First Officer Matthew Bell had almost no control of the plane, but the autopilot was working normally because it used a different control system. Both men struggled to breathe.
The report also notes at least two shipments of lithium-ion batteries, which should have been declared hazardous materials, were in containers “beneath the area of interest, due to systems indications on the flight recorders”.
The company sending those particular shipments was not identified in the report.
“While the shipper indicated that testing of the batteries was completed in accordance with [United Nations] standards, no UN test report was provided to verify that such tests were completed,” the report said.
Since 2006, 34 aviation incidents related to batteries and battery-powered devices have been reported to the US Federal Aviation Administration, and 22 of those involved lithium-ion batteries. Of 34 incidents, 22 involved fire.
The investigation continues “with further testing and detailed analysis currently ongoing”. Main testing should be completed this year, and a final report is due next year.