The plane crash in Clonbollogue has left at least two people with injuries, feared to be serious.
The crash happened shortly after the plane took off from the airfield at around 2.30pm.
Their bodies were recovered around 10pm and taken to Tullamore Regional Hospital where a post mortem will be carried out.
Rescue crews, Gardai and a team from the Air Accident Investigation Unit are at the scene.
An eye witness described the plane descending "like a torpedo" before it crashed. "That's all I know", he said from the crash scene.
It's understood the crash occurred between Daingean and Edenderry.
16 parachutists had made their jumps moments earlier before the plane crashed on bogland with the man and boy on board.
All 16 made their jump from the craft.
Members of the Civil Defence, Offaly Fire Services, and gardaí set up a road block not far from the crash site and a number of local people attended the scene.
"Sitting in the garden having our lunch and we heard the plane going up - because we often hear the parachute plane going up - we always listen out for it because it has a distinctive noise", said Ms Lynch. And normally it does that because it lets the parachuters go.