A family member of one of the men on board said the engine stopped working midair before the crash near Knightdale.
Questions remain as the NTSB investigates the deadly plane crash that killed former NASCAR driver Greg Biffle and his family
All 67 people on board Flight 5342 and the helicopter were killed when they collided as the jet approached Reagan National.
The NTSB concluded three days of investigative hearings on Friday.
During the second of three days of witness testimony and public inquiry by the National Transportation Safety Board into the January midair crash over the Potomac River, the board focused on air traffic control.
Investigators probing the January midair collision of a passenger plane and an Army helicopter over Washington that killed 67 people found the chopper was flying higher than the it should have been and the altitude readings were inaccurate.