(BIRMINGHAM, Alabama) CNN — BIRMINGHAM, Alabama (CNN) -- The National Transportation Safety Board on Thursday recovered data recorders from the UPS plane that crashed this week in Birmingham, NTSB spokeswoman Kelly Nantel said. The recorders will be taken to Washington for examination later in the day.
Investigators had to use picks and shovels to retrieve the data recorders from the wreckage because flames in the plane's tail section kept officials from accessing them immediately.
The devices could help investigators determine why the plane which did not issue a distress call went down early Wednesday while on approach to the Birmingham-Shuttlesworth International Airport.
The Airbus A300-600F broke into pieces killing the pilot and a co-pilot as it crashed around 4:45 a.m. in an open field near a street that runs parallel to the airport.
The cargo plane had 12 "service difficulty" reports on file at the Federal Aviation Administration, including at least two that the reports indicated led pilots to declare emergencies.
But an aviation expert told CNN he believes none of the previous problems would have played a role in Wednesday's accident.
The reports document problems ranging from an inoperative light in an emergency exit light assembly to a problem with the plane's flaps.
"I don't see anything there that indicates in any way that its related to the events in Birmingham," said John Goglia, a former NTSB member and former certificated aircraft mechanic.
The flap problem, reported in 2006 while the plane was flying in Germany, might raise concern had it not occurred so long ago, he said.
Witnesses said the plane, which took off from Louisville, Kentucky, flew low over a neighborhood, striking the tops of trees and knocking down power lines as it crashed.
The crash site is about a half-mile north of a runway.
A photo showing the jet engine blades only partially damaged could indicate that the engines were not running or were at "very low idle" upon impact, instead of the faster "flight idle" typical upon landing, Goglia said.
"An engine that is producing power, those (blades) would have been gone," said Goglia. The lack of damage suggests that "they weren't spinning so fast and they stopped quickly."
If the data recorders contain information, investigators should be able to quickly discover the status of the engines before impact.
But if the data is not retrievable, investigators will focus on the condition of the blades, Goglia predicted.
Airbus said Wednesday the plane had approximately 11,000 flight hours in some 6,800 flights. It was powered by Pratt & Whitney engines.
The plane was one of two flights UPS sends to Birmingham each day, company spokesman Mike Mangeot told CNN affiliate WBRC.
The crew did not report any trouble, Birmingham Mayor William Bell said, citing conversations with control tower officials. Light showers and a visibility of 10 miles were reported in the area of the airport at the time of the crash, according to CNN meteorologist Dave Hennen.