The Civil Aviation Authority’s Air Accident Investigation Branch will try and determine how the light aircraft came down in Co Armagh.
A pilot and his passenger were taken to hospital after their plane crash-landed on an airstrip at Mullahead Road, Tandragee around 4 pm on Wednesday.
The PSNI and the emergency services were tasked to the scene following an emergency call out.
One man was treated in intensive care in Craigavon Area Hospital.
His condition is described as stable on Thursday while the second man was transferred to another hospital but his condition is not known.