NTSB: Day 3 of investigation could yield data from plane's black boxes

NTSB Senior Investigator Joe Sedor (left) shows Member Robert Sumwalt (right) the debris field stemming from the crash of UPS Flight 354, Friday, August 16, 2013. (NTSB Photo)

In its third day of investigation into a deadly UPS plane crash, the National Transportation Safety Board expects to learn more from data retrieved from the plane's "black box" flight data recorders.

The plane crashed Wednesday morning on the property of the Birmingham-Shuttlesworth Airport, killing two pilots.

NTSB board member Robert Sumwalt says details may be released during a press conference Friday on whether the data is good enough to reveal what caused the crash. Investigators began looking into the boxes Thursday night in Washington, D.C.

Local avionics expert Lewis Holder tells ABC 33/40 the boxes hold vital information, including the plane's pitch, speed, acceleration and flight control inputs. He also says the digital equipment more than likely contains voice recording information that could shed light on what was said and heard as the plane descended.

NTSB will release more details during a news conference at 4 p.m.

Stay with ABC 33/40 for more on this developing story